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BATTERY SERVICE MANUAL Thirteenth Edition

Published By: BBattery Counci l International

Headquarters: 401 North Michigan Avenue, Chicago, Illinois 60611-4267 Phone: (312) 644-6610 Fax: (312) 527-6640

info@batterycouncil.org www.batterycouncil.org

©2010 Battery Council International. All Rights Reserved.

Foreword

The Battery Council International presents this revised Thirteenth Edition of the Battery Service Manual with the hope that it will be useful in addressing your battery problems and questions. The information contained in this manual represents the input of some of the most capable technical representatives in the battery industry today.

We are deeply indebted to numerous members of BCI, in particular those on the Technical Committee, for the many hours they devoted to making this publication current with the latest technology in the battery industry.

A special debt of gratitude is extended to the following individuals and their companies, for the extra effort they put forth in the update of this manual:

Especially to Mr. Robert Flicker, East Penn Manufacturing Company for recognizing the need to update the manual and for his guidance and leadership in seeing the project through to completion. We would also like to thank the Bitrode Corporation for their help and support in completing this project.

Gordon Beckley, Trojan Battery Company

David Boden, Ph.D., Hammond Group, Inc.

George H. Brilmyer, Ph.D., Atraverda Limited

Robert Flicker and Scott McCaskey, East Penn Manufacturing Company

Mike Fraley, Crown Battery Manufacturing

John Gagge and Dana Kowalski, EnerSys

Robert Gruenstern, Maggie Teliska, Ph.D. and Jeffrey Zagrodnik, Johnson Controls, Inc.

Jim Hubbman and Ron Schaefer, formerly with Bitrode Corporation

Richard Johnson and John Miller, Exide Technologies

James Klang, Midtronics, Inc.

Rich Rymond, Ford Motor Company

Joe Semens, Interstate Battery Systems of America

George Zguris, Hollingsworth & Vose Company

BCI recognizes that many other individuals provided time, energy and expertise to make this update possible. Their endeavors are also sincerely appreciated.

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Table of Contents

Chapter Page 1 Common Battery Terms .......................................................................................1

2 Safety Precautions ..................................................................................................4

3 How a Battery Works ............................................................................................6

4 Battery Construction ............................................................................................12

5 Manufacturing Processes ....................................................................................18

6 Starting Batteries ..................................................................................................21

7 Golf Car, Deep Cycle Marine and Other Cycling Batteries ...................26

8 Battery Ratings .......................................................................................................30

9 Receiving New Battery Shipments ...................................................................31

10 Battery Stock Maintenance ................................................................................32

11 New Battery Installation .....................................................................................34

12 Servicing Battery in the Vehicle ......................................................................39

13 Charging Methods .................................................................................................41

14 Causes of Battery Failure ...................................................................................44

15 Automotive Charging Systems ..........................................................................49

16 VRLA Batteries .......................................................................................................52

Index ...........................................................................................................................59

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Chapter 1 COMMON BATTERY TERMS

ACTIVE MATERIAL — The porous structure of lead compounds that produce and store electrical energy within a lead-acid battery. The active material in the positive plates is lead dioxide and that in the negative is metallic sponge lead. When an electrical circuit is created, these materials react with sulfuric acid during charging and discharging according to the following chemical reaction:

PbO2 + Pb + 2H2SO4 = 2PbSO4 + 2H2O.

AGM (Absorbent Glass Mat) — A type of non-woven separator material comprised almost entirely of glass microfibers that absorbs and retains the electrolyte leaving no free electrolyte in the cell to spill. VRLA batteries made with this material are often referred to as “AGM” batteries.

AMPERE (Amp, A) — The unit of measure of the electron flow rate, or current, through a circuit.

AMPERE-HOUR (Amp-Hr, Ah) — A unit of measure for a battery's electrical storage capacity, obtained by multiplying the current in amperes by the time in hours of discharge. (Example: A battery that delivers 5 amperes for 20 hours delivers 5 amperes X 20 hours = 100 Amp-Hr of capacity.)

BOOST CHARGE — The process of ensuring that the cells and plates within a battery are charged sufficiently for the battery to perform its desired function. Boost charging is typically done for a short duration at a high current.

CAPACITY — The capacity of a battery is specified as the number of Amp-Hrs that the battery will deliver at a specific discharge rate and temperature. The capacity of a battery is not a constant value and is seen to decrease with increasing discharge rate. The capacity of a battery is affected by a number of factors such as: active material weight, density of the active material, adhesion of the active material to the grid, number, design and dimensions of plates, plate spacing, design of separators, specific gravity and quantity of available electrolyte, grid alloys, final limiting voltage, discharge rate, temperature, internal and external resistance, age, and life history of the battery.

CONTAINER AND COVER — The reservoir and lid containing the battery parts and electrolyte made from impact and acid resistant material such as polypropylene.

CELL — The basic electrochemical current-producing unit in a battery, consisting of a set of positive plates, negative plates, electrolyte, separators, and casing. In a lead-acid battery the cell has an open-circuit voltage of approximately 2 volts. There are six cells in a 12-volt lead-acid battery.

CIRCUIT — An electrical circuit is the path followed by a flow of electrons. A closed circuit is a complete path. An open circuit has a broken, or disconnected, path.

CIRCUIT (Series) — A circuit that has only one path for the flow of current. Batteries arranged in series are connected with negative of the first to positive of the second, negative of the

second to positive of the third, etc. If two 12-volt batteries of 50 ampere-hours capacity each are connected in series, the circuit voltage is equal to the sum of the two battery voltages, or 24 volts, and the ampere-hour capacity of the combination is 50 ampere-hours. (See Figure 13-2 for a diagram of a series connection of batteries.)

CIRCUIT (Parallel) — A circuit that provides more than one path for the flow of current. A parallel arrangement of batteries (usually of like voltages and capacities) has all positive terminals connected to a conductor and all negative terminals connected to another conductor. If two 12-volt batteries of 50 ampere-hour capacity each are connected in parallel, the circuit voltage is 12 volts, and the ampere-hour capacity of the combination is 100 ampere-hours. (See Figure 13-1 for a diagram of a parallel connection of batteries.)

COLD CRANK RATING — The cold crank rating refers to number of amperes a lead-acid battery at 0°F (-17.8°C) can deliver for 30 seconds and while maintaining at least 7.2 volts (1.2 volts per cell). This is commonly referred to as CCA (Cold Cranking Amps).

CONDUCTANCE — The ability to transmit current in a circuit or battery.

CORROSION — The chemical or electrochemical reaction between a material, usually a metal, and its environment that produces a deterioration of the material and its properties. The positive lead grids in a battery gradually corrode in service often leading to battery failure. Battery terminals are subject to corrosion if they are not properly maintained.

CURRENT — The rate of flow of electricity, or the movement of electrons along a conductor. It is comparable to the flow of a stream of water. The unit of measure for current is the ampere.

CURRENT (ALTERNATING) (AC) — A current that varies periodically in magnitude and direction. A battery does not deliver alternating current (AC).

CURRENT (DIRECT) (DC) — An electrical current flowing in an electrical circuit in one direction only. A secondary battery delivers direct current (DC) and must be recharged with direct current in the opposite direction of the discharge.

CYCLE — In a battery, one discharge plus one recharge equals one cycle.

DISCHARGING — When a battery is delivering current, it is said to be discharging.

ELECTROLYTE — In a lead-acid battery, the electrolyte is sulfuric acid diluted with water. It is a conductor that supplies water and sulfate for the electrochemical reaction:

PbO2 + Pb + 2H2SO4 = 2PbSO4 + 2H2O.

ELECTRONIC TESTER — An electronic device that assesses the condition of a battery through an ohmic measurement such

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as resistance or conductance, typically without drawing large current loads.

ELEMENT — A set of positive and negative plates assembled with separators.

EQUALIZATION CHARGE — The process of ensuring that the cells and plates within a battery are all at full charge and that the electrolyte is uniform and free of stratification. This is normally done by charging the battery under controlled conditions (charge current, time & upper voltage limits are usually specified).

FORMATION — In battery manufacturing, formation is the process of charging the battery for the first time. Electrochemically, formation changes the lead oxide paste on the positive grids into lead dioxide and the lead oxide paste on the negative grids into metallic sponge lead.

GEL — Electrolyte that has been immobilized by the addition of a chemical agent, normally fine silica, to prevent spillage. Batteries made with gelled electrolyte are often referred to as Gel batteries. Gel batteries are one typical type of VRLA battery.

GRID — A lead alloy framework that supports the active material of a battery plate and conducts current.

GROUND — The reference potential of a circuit. In automotive use, the result of attaching one battery cable to the body or frame of a vehicle that is used as a path for completing a circuit in lieu of a direct wire from a component. Today, over 99% of automotive and LTV applications, use the negative terminal of the battery as the ground.

HYDROMETER — A device used to measure the strength (i.e., the concentration of sulfuric acid in the electrolyte) of the electrolyte through specific gravity of the electrolyte.

INTERCELL CONNECTORS — Lead structures that connect adjoining cells in series, positive of one cell to the negative of the next, within a battery.

LOAD TESTER — An instrument that draws current (discharges) from a battery using an electrical load while measuring voltage. It determines the battery's ability to perform under actual discharge conditions.

LOW WATER LOSS BATTERY — A battery that does not require periodic water addition under normal driving conditions; also referred to as a maintenance-free battery.

MAINTENANCE FREE — A battery that normally requires no service watering during its lifetime of use.

NEGATIVE — Designating, or pertaining to, electrical potential. The negative battery terminal is the point from which electrons flow during discharge.

OHM — A unit for measuring electrical resistance or impedance within an electrical circuit.

OHM'S LAW — Expresses the relationship between volts (V) and amperes (A) in an electrical circuit with resistance (R). It can be expressed as follows:

V = IR

Volts (V) = Amperes (I) x Ohms (R). If any two of the three values are known, the third value can be calculated using the above equation.

OPEN CIRCUIT VOLTAGE — The voltage of a battery when it is not delivering or receiving power.

PLATES — Thin, flat structures comprised of a grid and active material. The grid supports the active material and conducts electrons out of the cell. Plates are either positive or negative, depending on the active material they hold.

POSITIVE — Designating, or pertaining to, a kind of electrical potential; opposite of negative. A point or terminal on a battery having higher relative electrical potential. The positive battery terminal is the point to which electrons flow during discharge.

PRIMARY BATTERY — A battery that can store and deliver electrical energy but cannot be recharged. A lead-acid battery is NOT a primary battery.

RESERVE CAPACITY RATING — The time in minutes that a new, fully charged battery will deliver 25 amperes at 27°C (80°F) and maintain a terminal voltage equal to, or higher than, 1.75 volts per cell. This rating represents the time the battery will continue to operate essential accessories if the alternator or generator of a vehicle fails.

RESISTANCE — The opposition to the free flow of current in a circuit or battery. It is commonly measured in Ohms.

SECONDARY BATTERY — A battery that can store and deliver electrical energy and can be recharged by passing direct current through it in a direction opposite to that of discharge. A lead-acid battery is a secondary battery.

SEPARATOR — A porous divider between the positive and negative plates in a cell that allows the flow of ionic current to pass through it, but not electronic current. Separators are made from numerous materials such as: polyethylene, polyvinyl chloride, rubber, glass fiber, cellulose, etc. (See Chapter 4 for a more in depth explanation of separators.)

SHORT CIRCUIT — An unintended current-bypass in an electric device or wiring. Outside the battery a short circuit is established when a conductive path is established between the two terminals of a battery. Inside a battery, a cell short circuit is the result of contact between the positive and negative plates and will cause a cell to discharge and render the battery useless.

SPECIFIC GRAVITY (Sp. Gr. or ‘SG’) — Specific Gravity is a measure of the electrolyte concentration in a battery. This measurement is based on the density of the electrolyte compared to the density of water and is typically determined by the use of a ‘hydrometer’ (see Hydrometer). By definition, the specific gravity of water is 1.00 and the specific gravity of the sulfuric acid electrolyte in a typical fully charged battery is 1.265-1.285. Specific gravity measurements are typically used to determine if the battery is fully charged or if the battery has a bad cell.

STATE OF CHARGE — The amount of deliverable low-rate electrical energy stored in a battery at a given time expressed as a percentage of the energy when fully charged and measured under the same discharge conditions. If the battery is fully charged the “State of Charge” is said to be 100%.

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STRATIFICATION — The unequal concentration of electrolyte due to density gradients from the bottom to the top of a cell. This condition is encountered most often in batteries recharged from a deep discharge at constant voltage without a great deal of gassing. Continued deep cycling of a ‘stratified’ battery will result in softening of the bottoms of the positive plates. Equalization charging is a way to avoid acid stratification.

SULFATION — The generation or conversion of the lead sulfate discharge in the plates to a state that resists normal recharge. Sulfation often develops when a battery is stored or cycled in a partially discharged state at warm temperatures.

TERMINALS — The electrical structures on the battery to which the external circuit is connected. Typically, batteries have either top-terminals (posts) or side-terminals. Some batteries have both types of terminals (dual-terminal).

VENTS — Mechanisms that allow gasses to escape from the battery while retaining the electrolyte within the case. Flame arresting vents typically contain porous disks that reduce the probability of an internal explosion as a result of an external spark. Vents come in both permanently fixed and removable designs.

VOLT — The unit of measure for electrical potential or voltage.

VOLTMETER — An electronic device used to measure voltage, normally in a digital format.

VOLTAGE DROP — The net difference in the electrical potential (voltage) when measured across a resistance or impedance (ohms). Its relationship to current is described in Ohm's law.

VRLA — Valve Regulated Lead Acid battery. AGM and Gel are the two types of VRLA batteries. These batteries have no “free” liquid electrolyte and in the cell operate on the oxygen recombination cycle, which is designed to minimize water loss. VRLA batteries feature vents that are one-way burp-valves. These low-pressure burp-valves prohibit air ingress to the cell while permitting gases to vent from the cell if necessary. The pressure maintained in the battery, though only very slight (<3psi) is required to facilitate the oxygen recombination reaction, which converts the oxygen generated at the positive plates back into water.

WATT — The unit for measuring electrical power, i.e., the rate of doing work, in moving electrons by, or against, an electrical potential. Formula: Watts = Amperes x Volts.

WATT-HOUR (Watt-Hr, WH) — The unit of measure for electrical energy expressed as Watts x Hours

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Chapter 2 SAFETY PRECAUTIONS

DANGER OF EXPLODING BATTERIES Batteries contain sulfuric acid and produce explosive mixtures of hydrogen and oxygen gas. Because self-discharge action generates hydrogen gas even when the battery is not in operation, make sure batteries are stored and used in a well-ventilated area. ALWAYS wear ANSI Z87.1 (U.S. standard) approved safety glasses and face shield or splash proof goggles when working on or near batteries:

• Always wear proper eye, face and hand protection.

• Keep all sparks, flames and cigarettes away from the battery.

• Never try to open a battery with non-removable vents. (See Figure 2-1 for the acceptable wording and symbols currently used on vent caps.)

• Keep removable vents tight and level except when servicing electrolyte.

• Make sure work area is well ventilated.

• Never lean over battery while boosting, testing or charging.

• Exercise caution when working with metallic tools or conductors to prevent short circuits and sparks.

• High voltage applications require special precautions to avoid electrocution hazards that may vary from application to application. Consult the application owner’s manual, service manuals and follow all warning labels.

SAFE CHARGING

Never attempt to charge a battery without first reviewing the instructions for the charger being used. In addition to the charger manufacturer's instructions, these general precautions should be followed:

• Always wear proper eye, face and hand protection.

• Always charge batteries in a well-ventilated area.

• Keep vents tight and level.

• Use an automatic voltage-controlled charger set for the correct battery type whenever possible to prevent problems if the battery cannot be monitored during charge.

• When making connections to a battery or disconnecting a battery, follow the instructions supplied with the charger with regard to (1) whether charger should be plugged in or not, (2) whether charger should be switched on or off, (3) in what order and where one should make the connections, and (4) whether charging in a vehicle is permitted and any special precautions to be followed when charging in a vehicle. Many chargers spark when turned off or turned on, whether plugged in or not. Some charger instructions

demand that the user (1) add a large cable, not supplied by the charger manufacturer, to the negative terminal, and (2) make the final connection to this cable, well away from the battery.

• Never try to charge a visibly damaged battery.

• Do not attempt to charge a frozen battery. Thaw it before attempting to charge.

• Make sure that the charger leads to the battery are not broken, frayed or loose.

• If the battery becomes hot, or if violent gassing or spewing of electrolyte occurs, reduce the charging rate or turn off the charger temporarily.

Figure 2-1: Danger/Poison Warning Message

HANDLING BATTERY ACID

Battery acid, or electrolyte, is a solution of sulfuric acid and water that can destroy clothing and burn the skin. Use extreme caution when handling electrolyte and keep an acid neutralizing solution - such as baking soda or household ammonia mixed with water - readily available. When handling batteries:

• Always wear proper eye, face and hand protection.

• If the electrolyte is splashed into an eye, immediately force the eye open and flood it with clean, cool water for at least 15 minutes. Get prompt medical attention.

• If electrolyte is taken internally, drink large quantities of water or milk. DO NOT induce vomiting. Get prompt medical attention.

• Neutralize with baking soda any electrolyte that spills on a vehicle or in the work area. After neutralizing, rinse contaminated area clean with water.

• Under no conditions should a consumer prepare or adjust the concentration of electrolyte using concentrated sulfuric acid.

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LIMITING THE HANDLING AND MEASUREMENT OF ELECTROLYTE IN A BATTERYHandling and measuring battery electrolyte can be dangerous and requires knowledge and training to avoid injury, skin irritation, damage to clothes and equipment. It is preferable for untrained personnel to use the measurement of battery voltage to

estimate battery condition rather than dealing with battery electrolyte. In numerous cases, there is no way of measuring the electrolyte in a battery. Many batteries with free liquid electrolyte are already sealed to prevent measurement and addition of fluids. VRLA batteries with gas tight seals such as AGM or Gel have no free electrolyte to measure even if their seals were opened.

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Chapter 3 HOW A BATTERY WORKS

A storage battery is an electrochemical device. It stores chemical energy that can be released as electrical energy upon demand. When the battery is connected to an external load, such as a starter, the chemical energy is converted into electrical energy and current flows through the circuit.

PURPOSE OF THE BATTERYThe three main functions of the automotive battery are to:

1. Supply power to the starter and ignition system so the engine can be cranked and started.

2. Supply key-off power or the extra power necessary when the vehicle's electrical load requirements exceed the supply from the charging system.

3. Act as a voltage stabilizer in the electrical system. The battery smoothes out or reduces high voltages (transient voltages) that occur in the vehicle's electrical system. These excessively high voltages could damage other components in the electrical system if it were not for the protection provided by the battery.

Storage batteries are used in other fields for a variety of tasks such as providing power for lighting units and propelling special vehicles, UPS (Uninterruptible Power Supply), load leveling, etc.

HOW IT OPERATESWhen two unlike electrode materials (such as the positive and negative plates of a lead acid battery) are immersed in an electrolyte solution (such as sulfuric acid and water), a voltage is developed and a battery is created. The voltage developed depends upon the types of materials used in the electrodes and the electrolyte used. The voltage is approximately from 2.1 to 2.2 volts per cell in a typical lead-acid battery and is dependent on the concentration of the sulfuric acid electrolyte. Electrical energy is produced by the chemical reaction between the different electrode materials and the electrolyte. When the chemical reaction starts, electrical energy flows from the battery as soon as there is a circuit between the positive and negative terminals (whenever a load such as the headlamps is connected to the battery). The electrical current flows as electrons through the outside circuit and as charged ions between the plates, inside the battery.

The voltage of the lead-acid storage battery is determined by the materials used in its construction. These chemicals are:

1. Lead dioxide (PbO2) - the material on the positive grid.

2. Sponge lead (Pb) - the material on the negative grid.

3. Sulfuric acid (H2SO4) - the electrolyte.

Discharge CycleWhen a battery is connected to an external load, current flows and it starts to discharge. The lead dioxide (PbO2) in the positive plate is a compound of lead (Pb) and oxygen (O). Sulfuric acid (H2SO4 in the electrolyte) is a compound of hydrogen cations (H+) and the sulfate anion (SO4

2—). As the battery discharges, lead dioxide (PbO2) in the active material of the positive plate combines with the hydrogen (H+) and sulfate (SO4

2—) ions from the sulfuric acid forming lead sulfate (PbSO4) and water (H2O) in the positive plate.

Concurrently, a similar reaction takes place at the negative plate. Lead (Pb) from the negative active material combines with sulfate ions (SO4

2—) from the sulfuric acid to form lead sulfate (PbSO4) in the negative plate.

As the discharge progresses, the specific gravity of the electrolyte is reduced by the consumption of sulfuric acid and the amount of water created by the reaction. The specific gravity can be measured with a hydrometer, which provides an estimate of the amount of discharge in a battery.

During discharge, the active material of both electrodes is being converted to nonconductive lead sulfate (PbSO4) and the acid concentration is becoming weaker. Consequently, the voltage drops, since it depends on the potential between the two plate materials (Pb and PbO2), the concentration of the electrolyte and the internal conductance of the battery if the current is high. Eventually the battery can no longer deliver electricity at a useful voltage, and it is said to be discharged.

When a battery is subjected to a high discharge rate, such as cranking an engine near 0°F (-17.8°C), for a prolonged period of time, it quickly becomes discharged. This is due to the fact that the acid circulation into the pores of the plates and the diffusion of water from the pores of the plates is too slow to sustain the discharge. A very small percentage of the electrolyte and the plate active materials in the cells can be used during the relatively short duration of a high rate discharge. Only the material on or near the plate surfaces takes part in the chemical reaction because of ionic conductance limitations. It is for this reason that automotive batteries must have large plate surface areas per cell. Porous, low-density plate materials retain larger amounts of electrolyte allowing longer sustained cold discharges.

The acid circulation-water diffusion condition described above has less of an effect on battery performance at lower discharge rates. At low discharge rates practically all of the acid may be consumed, and the material near the interior center of the plates has more of an opportunity to take part in the chemical reaction.

A discharged storage battery can be recharged (pass electrical current through it in the opposite direction of the discharge) and its active materials will be restored to their original composition. When fully recharged the battery is again ready to deliver its full power. This discharge, charge cycle can be repeated over and

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over until eventually plate or separator deterioration, or some other factor, causes the battery to fail.

Charge CycleThe chemical reactions that take place within a battery during charge are basically the reverse of those that occur during discharge. The sulfate (PbSO4) in both plates is split into its original form of lead (Pb) and sulfate (SO4). The water is split into hydrogen (H) and oxygen (O). The sulfate in the plates combines with the hydrogen in the water and is restored to sulfuric acid (H2SO4). At the same time, the oxygen with water combines chemically with the lead of the positive plate to form lead dioxide (PbO2). The specific gravity of the electrolyte increases during charge because sulfuric acid is being formed and is replacing water in the electrolyte.

When a battery is fully recharged, the charging process continues in what is called equalization charge. During equalization charge, a battery will evolve gases at the positive and negative plates. Hydrogen (H2) gas is produced at the negative plate and oxygen (O2) gas at the positive. These gases result from the decomposition of water (H2O). A battery gases (and uses water) because it is being charged at a higher rate than it can accept. This may be due to the fact that the battery is fully charged, that its plates are sulfated or that it is too cold to accept a charge. Generally, a battery will “gas” near the end of a charge because the charge rate is too high for the battery to accept all of it. A charger, which automatically reduces the charge rate as the battery approaches the fully charged state, eliminates most of this gassing. Refer to Chapter 13, "Charging Methods" for a more comprehensive description of the various types of chargers used to charge batteries.

It is extremely important not to charge low water loss batteries for long periods of time at rates that will cause them to gas heavily, because this means water is being decomposed, which in sealed batteries cannot be replaced. Of course, no battery should be overcharged for a long period because it will cause internal degradation of the components.

WHAT THE VEHICLE REQUIRESAs mentioned under "Purpose of the Battery", the primary function of the battery is to supply current to start the engine. The current required to crank an engine varies from vehicle to vehicle. Cranking current is dependent upon the engine stroke and bore, the number of cylinders, engine/starter gear ratio, the battery and circuit resistance, temperature, engine oil viscosity and the accessory loads. A four-cylinder engine may require as much cranking current as an eight-cylinder engine with greater displacement because it may need to crank faster to start. All of these factors are considered when an original equipment battery is specified by the vehicle manufacturer.

The second function of a battery is to supplement the vehicle load requirements whenever they exceed the charging system's ability to deliver the necessary power. Charging systems will carry all the electrical loads under normal driving conditions. However, if the engine is at "idle" speed, the battery may have to supply a portion of the accessory load. This may occur in city

driving or "stop and go" driving conditions with a normal accessory load. The battery will supply the vehicle's entire electrical load requirements if the charging system fails, until its capacity become exhausted.

The following chart gives several examples of the demands made on a typical automotive electrical system.

TYPICAL CURRENT LOADS OF PASSENGER CARS(Note: This list is not definitive, and is provided only for illustrative purposes.)

Amperes

Ignition ................................................................................ 2-9

Radio ............................................................................. 0.5 –5

Windshield Wipers .............................................................7.5

Headlamps (Low Beam, Dim) ...................................... 17-18

Headlamps (High Beam, Bright) .................................. 19-20

Parking Lights .................................................................. 4-10

Fog Lamps ..............................................................................8

Brake Lights...................................................................... 6-11

Interior Lights .................................................................... 2-4

Hood Light.................................................................... 0.5-1.0

Horn.........................................................................................4

Power Window (one window)...............................................5

ABS Brakes...................................................................14 max

Trunk Light ................................................................... 0.5-1.0

Blower (Heater, air conditioner) ................................... 10-14

Heated Rear Window Defogger .................................... 13-28

Heated Seat ......................................................................... 4-5

Power Seat Motor...........................................................10-13

Summer Starting (Gas) ..............................................150-200

(Diesel) .......................................................................450-550

Winter Starting (Gas) .................................................250-350

(Diesel) .......................................................................700-800

When replacing an automotive battery, it is recommended that you install a battery at least equivalent to the original equipment battery ratings.

The third function of the battery is to act as a voltage stabilizer in the charging system. Occasionally, very high transient voltages are generated in the electrical system. This may occur in making or breaking a circuit. Using its large capacitance the battery partially absorbs and reduces these peak voltages thereby protecting solid-state components from damage

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ELECTROLYTE AND SPECIFIC GRAVITYThe electrolyte in a lead-acid storage battery is a water-sulfuric acid solution. A battery with a fully charged specific gravity in a range of 1.26 to 1.32 corrected to 80°F (26.7°C) contains an electrolyte with approximately 35%-42% sulfuric acid by weight or 23%-28% by volume. The remainder of the electrolyte is water.

The sulfuric acid in the electrolyte is one of the necessary ingredients for the chemical reactions taking place inside the battery. It supplies the hydrogen (H+) and sulfate ions (SO4

2—)that combine with the active material in the plates. It is also the carrier for the ionic electric current as it passes from plate to plate. When the battery terminals are connected to an external load, the sulfate combines with the active materials of the positive and negative plates forming lead sulfate (PbSO4) on both and releasing electrical energy. Electrons flow from the negative terminal to the load (such as headlamps) and back to the positive terminal.

Specific gravity is a measurement for indirectly determining the sulfuric acid concentration of the electrolyte. The recommended fully charged specific gravity of most 12-volt batteries today is in the range of 1.26 - 1.32 corrected to 80°F (26.7°C). For full charge specific gravities and open circuit voltages of a particular battery, consult the manufacturer.

On the specific gravity scale, water by definition is 1.000. Therefore, electrolyte with a specific gravity of 1.285 means it is 1.285 times heavier per unit volume than pure water at the same temperature.

Water The recommended water to use for servicing a battery is distilled or de-ionized water. Do not use water with a known high mineral content. Avoid the use of metallic containers when storing acid or water. Distilled or demineralized water is recommended because mineral water contains metallic impurities that may lower the performance of the battery or cause high gassing and self-discharge. Many liquids such as salt water, vinegar, antifreeze and alcohol, or harmful acids such as nitric, hydrochloric or acetic, can harm a battery.

HYDROMETER—DESCRIPTION AND HOW TO USEThe state-of-charge of a lead acid battery can often be estimated by the specific gravity of the electrolyte (its weight compared to water). The specific gravity can be measured directly with a hydrometer or determined by the stabilized voltage.

Note: many maintenance-free batteries are not designed to be opened by the consumer. This procedure can not be performed on these inaccessible batteries. The caps may be glued, welded or physically locked in place. Do not attempt to force caps off or you may damage the battery. Never attempt to open a gel or AGM battery.

One type of hydrometer is a bulb-type syringe, which will extract electrolyte from the cell. A glass float in the hydrometer barrel is calibrated to read in terms of specific gravity. A common range of specific gravity used on these floats is 1.160

to 1.325. Do not assume a battery will not take a charge because you have been charging it for a while and the float will not rise. The battery may have been fully discharged and will require considerable charging and destratification before reaching the minimum specific gravity on the float.

Figure 3-1 (left): Service Station Hydrometer

Figure 3-2 (right): Correct method of reading hydrometer. Eye on level with liquid surface. Disregard curvature of liquid against glass parts.

The lower the float sinks in the electrolyte, the lower its specific gravity. Figure 3-2 illustrates the correct method for reading a hydrometer. The barrel must be held vertically so the float is not rubbing against the side of it. Draw an amount of acid into the barrel so that with the bulb fully expended, the float will be lifted free, touching neither the side, top or bottom stopper of the barrel. Your eye should be on a level with the surface of the liquid in the hydrometer barrel. Disregard the curvature of the liquid where the surface rises against the float stem and the barrel due to surface tension. (See Figure 3-2.) Keep the float clean. Check it often to be sure it is not cracked.

There is a newer type of electronic hydrometer that normally draws a small sample of the electrolyte and determines its specific gravity and displays it digitally on a read out. They normally range in its ability to read electrolyte from the strength of water (1.000) to well over battery strength. They are rapid, repeatable and easy to use.

The following table illustrates typical specific gravity values for a cell in various stages of charge for a typical new battery with corresponding voltage readings. This table, especially the discharged values, will vary considerably with different battery constructions due to changes in the ratio of electrolyte to active material.

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TYPICAL OPEN CIRCUIT VOLTAGE AND SPECIFIC GRAVITY VALUES FOR NEW BATTERIES*

(Note: This table is not definitive, and is provided only for illustrative purposes. Consult with the battery manufacturer for recommended full state-of-charge suggestions.)

Full Charge Specific Gravity 1.265 1.285 1.305

STATE OF CHARGE S.G. OCV * S.G. OCV * S.G. OCV *

100% 1.265 12.66 1.285 12.77 1.305 12.88

75% 1.235 12.50 1.255 12.61 1.260 12.64

50% 1.200 12.31 1.225 12.44 1.215 12.39

25% 1.165 12.12 1.185 12.22 1.160 12.09

DISCHARGED 1.130 11.90 1.140 12.00 1.105 11.80

*OCV of 12-volt battery. OCV of 6-volt battery is half that of a 12-volt battery.

Figure 3-3 pictorially illustrates the relationship between specific gravity readings and the combination of the sulfate from the acid with the positive and negative plates for various states of charge. In the illustration, the presence of sulfate ions is indicated by dark shading. A fully charged battery has all of the sulfate in the acid. As the battery discharges, some of the sulfate begins to appear on the plates. The acid becomes more dilute and its specific gravity drops as water replaces more of the sulfuric acid. A fully discharged battery has more sulfate in the plates than in the electrolyte. Please note that the illustration shows the hydrometer float sinking lower and lower in the electrolyte as the specific gravity decreases.

Never take a hydrometer reading immediately after water has been added to a cell. The water must be thoroughly mixed with the underlying electrolyte, by charging, before hydrometer readings are reliable. If a reading is being taken immediately after the battery has been subjected to prolonged cranking, it will be higher than the true value. The water formed in the plates during the rapid discharge has not had time to mix with the higher specific gravity above the plates.

Temperature Correction

Hydrometer floats are calibrated to give a true reading at one fixed temperature only. A correction factor must be applied for any specific gravity reading made when the electrolyte temperature is not 80°F (26.7°C). Some standard hydrometers use a reference temperature of 60°F (15.5°C). Other hydrometer scales also exist. Some may require additional corrections. A temperature correction must be used because the electrolyte will expand and become less dense when heated. The float will sink lower in the less dense solution and give a lower specific gravity reading. The opposite occurs if the electrolyte is cooled. It will shrink in volume, becoming denser. The float will rise higher and give a false high reading.

Regardless of the reference temperature used as a standard, a correction factor of 0.004 specific gravity (sometimes referred to as 4 "points of gravity") is used for each 10°F (5.5°C) change in

temperature. Four "points of gravity" (.004) are added to the indicated reading each 10°F (5.5°C) increment above 80°F (26.7°C) and four points are subtracted for each 10°F (5.5°C) drop below 80°F (26.7°C). This correction is important at temperature extremes because it can be a substantial value.

Figure 3-3: Specific gravity and sulfate distribution

The electrolyte should be drawn in and out of the hydrometer barrel a few times to bring the temperature of the hydrometer float and barrel to that of the electrolyte in the cell.

Figure 3-4 illustrates the correction for hydrometer readings when the electrolyte temperature is above or below 80°F (26.7°C). In example No. 1, in cold weather, a dealer might

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install a partially discharged battery in a car at +20°F (—6.7°C). A hydrometer reading of 1.250 would indicate that the battery is reasonably charged. However, when the correction factor is applied, the true value is only 1.226.

Example No. 2 could be encountered in a battery exposed to the sun in hot weather; also, electrolyte can easily exceed 110°F (43°C) in car service in warm weather. The 1.235 specific gravity reading might indicate too low a state of charge to install in a car or that there is a problem with the electrical system if the battery is in service. However, the true reading of 1.243 may not be unreasonably low depending on the length of storage of the battery or the type of service that it has been experiencing in the car.

Figure 3-4: Thermometer showing Celsius, Fahrenheit and correction factors

TROPICAL AND ARCTIC CLIMATES

Most batteries used in temperate climates have a fully charged specific gravity in the 1.250 to 1.300 range. A fully charged electrolyte specific gravity of 1.210 to 1.230 is used in tropical climates. A tropical climate is considered one in which water never freezes. The lower strength electrolyte does not deteriorate the separators and grids as fast as a higher specific gravity electrolyte thereby increasing the service life of the battery.

However, lower specific gravity decreases the electrical capacity of the battery, especially the Cold Cranking Performance. This loss is offset by the fact that the battery is operating at warm temperatures where it is more efficient and Cold Cranking Performance is not required.

Batteries prepared for service in extremely cold weather use a higher specific gravity electrolyte. In some instances specific gravities of 1.290 to 1.300 are used. The Cold Cranking Performance increases as the specific gravity is increased until a value around 1.300 is reached. It should be noted that higher specific gravities decrease the service life of a battery.

As a battery approaches the discharged state, the easier it becomes for the electrolyte to freeze. However, a fully charged battery can be stored at subfreezing temperatures without freezing the electrolyte. The self-discharge rate of the battery at sub-freezing temperatures is so low that it will not require a recharge for many months.

Figure 3-5 shows the approximate freezing points of electrolyte at various specific gravities.

Figure 3-5: Electrolyte Freezing Points

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BATTERY CONSTRUCTION

Figure 4-1: Battery Construction

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Chapter 4 BATTERY CONSTRUCTION

In this chapter the individual parts of a battery will be discussed to provide fundamental information concerning its construction. Each part of the battery will be discussed separately, beginning with the plate grid and progressing to the complete battery assembly.

GRIDS

The grids are the supporting framework for the active material of the plates. They also conduct the current to and from the active material on the plates. They are typically rectangular mesh structures with a lattice of lead wires channeling current to a tab or lug connector at the top of the grid.

Grids typically contain additions of alloying metals added to soft lead so that the grids can be handled during the manufacturing process without being bent or damaged. With maintenance free batteries, grids are typically made from an alloy of lead, calcium and tin, to strengthen and stiffen the soft lead. Corrosion resistance and other common failure modes are also taken into consideration in alloy selection.

Figure 4-2: Standard radial grid with lug slightly off center

The addition of antimony to an alloy also stiffens lead and enhances the battery’s ability to cycle, but causes gassing side reactions that require maintenance. In the past when maintenance additions of water to batteries were normal, antimony percentages of 3-5% were not uncommon for automotive battery grid alloys. These alloys are still used in deep cycle applications that require maintenance. Manufacturers of batteries for SLI applications may still use antimony in the

positive grids to enhance cycle ability or recharge ability for special applications but at lower percentages, typically 1.5-2 percent, which reduces the gassing rate of the battery substantially.

Figure 4-3: Example of Expanded Metal Grid

Figure 4-4: Example Punched Grid

Small amounts of other metals are used in the lead alloy to obtain various other desired attributes.

POSITIVE AND NEGATIVE PLATES The first step in making a positive or negative plate is to paste a material (which has the consistency of firm mud) onto a grid.

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This paste is a mixture of lead oxide, sulfuric acid and water. Other additives, such as fibers to help bind the active material together, are often incorporated into this paste mix. The main difference between the paste used for the positive and negative plates is that "expanders" are added to the negative paste. These "expanders" are required to maintain the fine internal surface area and prevent the negative material from contracting in service and reverting to a dense, inactive state. Common expanders are blends of varying percentages of lignin, barium sulfate and carbon black.

After the plates have been pasted and cured (chem-set or hydroset), the positive plate is light or dark orange in color depending on curing conditions. The negative plates are gray in color due to the carbon black used in the expander.

SEPARATORS

Separators are thin sheets of electrically insulating, porous material that are used as spacers between the positive and negative plates to prevent electrical short circuits within the cells. Fine pores in the separators allow ionic current flow between the positive and negative plates.

The important characteristics of a separator are uniform thickness, oxidation resistance, low ionic electrical resistance, high porosity, small pore size and distribution and wetability. Generally, the ribs on a separator face the positive plate thereby providing greater acid volume next to the positives and minimizing the area of separator contact to protect the separator from the highly corrosive positive paste. The ribs also provide

space to improve acid circulation and to permit any gasses formed between the plates to rise to the surface of the electrolyte.

Today, most flooded automotive batteries use envelope style separators, with the separator generally folded around the bottom of the plate and sealed on the sides. The envelopes are open at the top to allow the gases generated at the plate surfaces to escape. Only one plate polarity needs to be enveloped to keep the electrodes separate. Enveloped separators are usually made from a silica/polyethylene material that can be readily folded and sealed. Enveloped plates can rest directly on the bottom of the container. This, in effect, increases the amount of electrolyte over the tops of the plates and results in increased battery life.

Another battery design uses leaf separator construction. Leaf separators are single sheets that are inserted between the plates as shown in Figure 4-5. The separators may be made of latex-impregnated glass fiber, resin-impregnated cellulose fibers, sintered PVC, silica/PVC or silica/rubber. Batteries using leaf separators require a sediment space in the bottom of the container. (Today, leaf separators are more commonly found in batteries designed for high cycling, non-automotive, applications).

Sometimes, a thin glass fiber or polymeric fiber mat may be attached to the ribs of these separators to retard the loss of active material under conditions of excessive vibration and deep cycling. A highly porous mat provides ample space for acid circulation.

Figure 4-5: Element Construction – Conventional Battery

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Another method of plate separation is that used in some types of valve regulated batteries. The plates are wrapped in an acid absorbent glass mat (AGM) separator material. Either the positive or negative plates are wrapped, but typically not sealed, because there is no free electrolyte to carry potential shorting sludge outside the plates. AGM separators permit the transfer of oxygen gas from the positive to the negative plate, where a recombination reaction occurs, thus suppressing gassing under normal conditions. As compared to open glass retainer mats, this AGM material is a fleece-like material that is highly porous but has much smaller pores. It bridges the entire gap between the electrodes and is typically kept under compression to mechanically support the active material and to aid in deep cycling capability.

ELEMENTS Individual cells are made by alternating positive plates and negative plates together in a group, with separators in between, and straps connecting the like polarity plates. This is known as an element. There is one element per battery cell. Any number or size of plates can be used in an assembly, depending upon the

desired performance and battery dimensions. A greater number of plates or larger plate size generally means more battery capacity. For example, a greater number of plates, or larger plates, will increase the total plate surface area per element. This increased surface area will maintain a higher voltage during discharge at high rates such as cranking an engine at low temperatures. The higher the voltage at the starter, the faster and longer the starter will crank the engine. However, the open circuit voltage (battery not connected to a charge or discharge load) of a single cell at full charge will still be about 2.1 volts, regardless of the size or number of plates because the voltage is driven by electrochemical difference between the charged positive and negative plates.

The elements are then placed in the cells of the container and the straps of one cell are connected to the straps of the adjacent cell or to an outside terminal. See "Cell Connectors" below for a description of the various methods used to make these connections. This method of construction connects all the cells in series so that the voltage of the completed battery equals the sum of the voltages of the individual cells (For example 2.1 volts per cell x 6 cells = 12.6 volts per battery)

Figure 4-6: Battery Element

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CELL CONNECTORS

As mentioned above, the cells of a battery are connected in series and the battery voltage equals the sum of the individual cell voltages. Construction techniques commonly used today connect the elements through holes in the cell partitions before the cover is placed on the battery. (See Figure 4-7.) The inter-cell connectors are bonded together though various welding techniques to connect all the cells in series and complete the battery circuit. This type of construction results in a shorter, low resistance path through the battery and yields higher discharge voltages when compared to external connector or over the partition construction techniques.

Connectors must be large enough to carry high cranking currents and be corrosion resistant to prevent cracking in service.

Figure 4-7: Examples of Cell Connectors

CONTAINER COVERS

Most automotive battery covers are made of polypropylene. Lead bushings are molded into the cover for the terminal posts. (Note: On side terminal batteries, these are molded into the containers.)

The vent wells on the under side of the cover are designed to provide the proper space above the electrolyte in order to permit gas to vent from the cells without forcing electrolyte from the battery.

Maintenance free designs, where water addition is not needed through battery life may have a cover and vent design that does not allow access to the electrolyte. Although these batteries are sometimes called “sealed,” they include vents to allow battery gases to escape freely to the atmosphere. VRLA batteries will contain pressure valves in their vent/cover area to aid in recombination (see Chapter 16). In order to assure proper operation these pressure vents should not be disturbed.

CONTAINER

Figure 4-8: Battery Container

The outside case or shell of the battery is typically a one-piece, rectangular shaped container with partitions to define the appropriate number of cells. As with the covers, most automotive battery containers are made of polypropylene. Containers and covers are designed to:

1. Withstand temperature extremes.

2. Resist mechanical damage.

3. Resist acid absorption and chemical attack.

Normally with enveloped plates, elements rest directly on the bottom of the container. The partitions typically have ribs so that elements that do not fill the entire gap between the partitions will not be free to move. Each partition typically has a hole near the top through which intercell connectors are welded.

Batteries with leaf separators require that the interior bottom portion of the container has what are called element rests or "bridges" running the full length of each cell. The space below the tops of the rests acts as a sediment chamber for the collection of active material that has been shed from the plates and will help prevent the sediment from shorting across the bottom of the plates.

COVER TO CONTAINER SEAL

The cover to container seal must not allow acid leakage; neither should the seal between cover and cell partitions allow for inter-cell leakage. Intercell leaks will increase the self-discharge rate of the battery.

Plastic one-piece covers and containers are usually sealed together by a high temperature and pressure process known as "heat sealing" or thermal welding. Adhesive bonding techniques are rarely used anymore.

FORMATION

The next step in the manufacture of a battery is to electrically "form" it in a sulfuric acid electrolyte solution. This initial charge electrochemically converts the lead oxide of the positive

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plate to lead dioxide. Lead dioxide is a highly porous material, which allows electrolyte to freely penetrate the plate. The positive plate once formed is a dark, chocolate brown color.

The "forming" charge converts the lead oxide of the negative plate to a dark gray, sponge lead. The "spongy" lead also allows the electrolyte to penetrate freely and allows the material beneath the plate surface to take part in the chemical reactions. (See Chapter 5 for the formation of dry charged batteries.)

The formation of a battery requires significant electrical current and can cause a great deal of heating, which can be detrimental to subsequent battery performance. Batteries are often charged with restrictive rates to keep them from getting too hot. Providing external cooling is often done to speed up the process.

Formation electrolyte is often chosen so that at the end of formation the battery will have an electrolyte concentration that is used in service. Batteries are also formed in weaker electrolyte because the formation process is more efficient, but at the end, the electrolyte must be drained and refilled with a stronger concentration so that the battery will achieve the proper final service concentration.

VENT CAPS

Vent plugs of various designs are currently used in the industry. Most include baffles so gasses can escape from the cells, while allowing electrolyte splashed into the vents to drain back and not be "pumped" from the battery by the escaping gasses.

If an individual vent plug is used for each cell, it may be threaded so that it screws into the vent well, or it may be pushed into the vent well and held in place by an interference fit.

The "push-in" type of vent plug may be a single plug, a three or six plug manifold (gang vent plug) or in a flexible plastic strip. These designs were developed to reduce the time required to seat or remove vent plugs and to direct gas through special channels.

A third type of vent is directly sealed on to the cover in a similar process to the cover to container sealing process

An important development in the design of vent plugs for the automotive battery was the introduction of the "flame arrester." Flame arresters are currently used in most batteries. At times, even during normal operation, the headspace in a battery may contain an explosive mixture of hydrogen with oxygen and air. If the gases vented from the battery are ignited by an external source, the flame arrester greatly reduces the likelihood that the vent will allow the flame to propagate into the headspace of the battery. The presence of a flame arrester does not mean that one can ignore any of the safety warnings in Chapter 2, such as those requiring the use of eye protection, the avoidance ignition sources and proper ventilation.

Flame arresters can be made of several materials, including sintered plastics and ceramics. They must be sufficiently porous to allow passage of large quantities of gases while still maintaining a low backpressure; they cannot however, be so porous as to allow the flame front to pass through them.

Another type of flame arrester has several tiny vent holes in the gang vent. The holes are small enough, and the vent so designed,

that the flame is snuffed out before it can ignite the gases. The heat of the flame front could melt the plastic around the opening of any one hole and seal it, but the other openings will still be available to vent the cells.

Some low water loss batteries do not use vent plugs. Instead, the gas is vented through one or two baffled labyrinths in the cover. The flame arrester in this type of design is placed at the exits of these intricate passageways.

There is limited use of elaborate vent plugs or vent labyrinths to prevent spillage on inversion of a flooded battery. These have largely been supplanted by unspillable AGM and Gel batteries. AGM and Gel batteries are unique in that they incorporate a pressure relief valve in their vent designs.

TERMINAL DESIGNS

Figure 4-9: Common Terminal Designs

Tapered Top Terminal This design uses tapered terminal posts built to SAE (Society of Automotive Engineers) dimensional standards so that all cable clamps will fit any battery with these posts. The positive terminal is slightly larger than the negative to minimize the danger of installing a battery in reverse. The positive terminal is 11/16" (17.5mm) in diameter at the top. The negative terminal is 5/8" (15.9mm) at the top. The minimum height of the terminal is 5/8" (15.9mm). Various other terminal dimensions and designs are sometimes used outside of North America.

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Side Terminals

These terminals are typically molded into the sidewall of the container near the top edge (see Figure 4-9). Each battery cable has a round lead faceplate that is compressed against the side terminal face by a bolt, which threads into the terminal. It is the contact between the two faces that provides the necessary low resistance connection, not the bolt. When tightening the bolt, use the manufacturer's recommended torque values to prevent terminal damage, while still insuring a good connection. NEVER over-torque. For more information, refer to Chapter 11 regarding new battery installation.

The "L" Terminal The "L" terminal is used on a few European car batteries. The "L" terminal is, however, used extensively on special application batteries used in lawn and garden equipment, snowmobiles, and light duty vehicles.

Stud Terminal Another type of "top" terminal is a threaded or "stud" terminal typically used on heavy duty batteries. Detailed dimensions of this terminal are given in SAE Specification J537.

THE COMPLETE ASSEMBLY

Figure 4-10 shows the complete battery assembly. The internal components, i.e., element, plates - are shown in their relative positions in the container. The external components of the battery are also shown in their relative positions.

Figure 4-10: The Complete Assembly

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Chapter 5 MANUFACTURING PROCESSES

INTRODUCTIONThe processes used to manufacture lead acid batteries have evolved considerably over the past several decades. Many of these process developments have resulted in improved battery performance, quality and reliability. Another basis for these changes has been the ongoing progression toward continuous processes and automation to reduce manufacturing cost. Many of the basic processes used in the manufacture of an automotive battery are the same regardless of the type or specific model of battery produced.

OXIDELead Oxide (PbO), required for the plate paste material, is made primarily by two methods, both of which combine lead (Pb) with oxygen (O2) from the air. One method uses a ball or attrition mill, frequently referred to as a Ball Mill. Moist air flows over hot pure lead balls, slugs or pigs that are being tumbled in the revolving drum of the mill. Lead oxide forms on the surface of the lead and is knocked off by contact with the tumbling lead. In one type of Ball Mill, the oxide is removed by a stream of air and collected in a dust collector. In another version of a Ball Mill, the oxide exits the mill via gravity feed.

A second widely used method of lead oxide production is the Barton process. In this process, air is passed across the surface of stirred, molten lead, forming lead oxide that is then picked up by an air stream and conveyed to a collector. The size and reactivity of the particles can be controlled by classifiers and hammer mills.

Most lead oxide used in automotive batteries, regardless how manufactured, contains 65% to 85% lead oxide (PbO), with the balance remaining as free lead (Pb). The particle size and reactivity of the oxide has a large impact on paste properties and subsequent battery performance.

GRIDSGrids are normally made from an alloy of lead. Pure lead is too soft to withstand the rigors of the manufacturing process. Alloyed lead is harder than pure lead and therefore more capable of being processed.

The grid alloy consists of pure lead that is blended with small percentages of other metals such as calcium and tin. Grid alloys used in cycling batteries often contain antimony with additions of tin and arsenic.

For many years battery grids were gravity cast individually (or in pairs) in book-type molds. To increase production speeds, grids are also made in a continuous operation by progressively expanding a moving strip of lead to form the grid mesh configuration commonly referred to as expanded metal. (See Figure 4-3.) There are also other continuous grid processes such

as direct casting against a rotating drum mold or punching grids directly from a strip of lead.

PASTE MIXINGBattery paste is the precursor of the active material in the battery. The paste is made with various percentages of lead oxide, water and sulfuric acid. The water and acid are added to the lead oxide at appropriate times, in the required amounts and mixed to obtain a paste with desired properties of density and consistency. Expander materials are added to the negative paste. (See Chapter 4, "Positive and Negative Plates" for a description of expander material.) Other additives such as fibers, anti-oxidants, etc., may also be added to the positive or negative paste.

PLATE PASTINGGenerally the paste is dumped from the paste mixer into the hopper of the plate paster, located below it. Paste is applied to the grids as they travel through the pasting machine. One type of plate paster is a "belt" paster in which the grids are conveyed through the pasting operation on a belt. In a belt paster operation, the paste is pressed into the grid from above. The belt stiffens the paste by removing part of the water allowing the resultant plates to be conveyed for further processing without damage.

Another type of paster is the "orifice" plate paster. In this type of paster, the grids pass through a preset opening while paste is applied from the top and bottom. There are other variations of these two basic types of pasting machines; some of which are capable of pasting a continuous strip of expanded grid mesh or other continuous grid designs.

In continuous operations such as expanded metal, a thin sheet of pasting paper is normally applied to each side of the strip pasted plates, allowing the plates to be separated from the pasting machine and then cut into individual plates without losing paste in the cutting area.

After the plates leave the pasting machine, they typically pass through an oven where the plates are partially dried. This “flash” drying process removes the excess surface moisture from the plates, which prevents the plates from sticking together, thereby making them easier to process. Sufficient moisture is retained in the plates to allow optimum curing parameters. At this point the plates are typically stacked together either vertically or horizontally in preparation for the curing process.

A pasted plate thickness is usually 0.003 to 0.015 inches (0.08 to 0.38mm) greater than the grid thickness – usually termed as the amount of plate “over-paste”.

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CURINGThe next step in the manufacture of an automotive lead-acid battery is the curing of the plates (sometimes referred to as chem-set or hydroset). After the plates are pasted, the paste contains approximately 10-20% free lead with the remainder being lead oxide, basic lead sulfates and moisture. In curing, a crystallization reaction takes place that grows and interlocks the crystals of the paste and binds it to the grid. Heat for this reaction (and to help dry the plates) is spontaneously provided by the oxidation of practically all of the free lead in the paste to lead oxide. Curing also requires a controlled amount of residual moisture in the paste for the crystallization reactions to occur optimally. This type of curing can take place in a warm room with naturally modulating humidity from the curing process. When the curing is complete, the plates are dry and strong, and the paste adheres tightly to the grids.

Curing under the above conditions requires two to four days. If the ambient temperature is too low, or the plates are allowed to dry too quickly, the reaction will be reduced and the plates may not cure properly. It is also possible to enhance the curing environment by controlling the temperature and humidity profile, thereby optimizing the curing reactions and reducing the required curing time. The positive or negative plates from this type of curing process have a tribasic lead sulfate crystal structure.

Another method of curing, typically applied to some positive plates, is to process the plates in a high temperature and humidity controlled room or steam chamber. This type of curing process produces plates with a tetrabasic lead sulfate crystal structure. The curing time, under these controlled conditions, may be shorter and the tetrabasic type of crystal form of the lead sulfate in the cured plate can be more uniform and controlled. This type of positive plate structure normally results in improved battery durability and capacity efficiency.

After curing, the plates may also be completely dried to further stiffen the plates and eliminate variable amounts of water, which may otherwise interfere with typical assembled element quality tests.

The cured positive and negative plates are then assembled into batteries as described below (also see Chapter 4).

BATTERY ASSEMBLY PROCESSESThe next series of basic steps in battery manufacturing involve the connecting together of the cured positive and negative plates along with the other battery components into a completed battery assembly. In most current day battery plants the assembly processes are completed on automated and continuous production lines or assembly cells.

The first assembly step is to intermittently stack positive and negative plates along with separators into single cell elements, according to the specific design. In most current automotive designs, the separators are interspaced, wrapped and edge-sealed around positive or negative plates to prevent physical contact with the opposite plates. While this stacking and wrapping process can be accomplished manually, in most cases it is now performed by high-speed automatic machines.

Next, the individual plate lugs at the tops of the cell elements are fused together – all positives together, and separately, all negatives together. This can be accomplished manually by torch welding (or soldering) the lugs to lead-alloy connecting straps. Today, however, most manufacturers us an automated Cast-on-Strap (COS) process. The COS process basically holds cell groupings within a defined and controlled physical arrangement while the respective lugs are submerged into strap molds that have been filled with molten lead alloy. After a specified and controlled cooling time, the groups are then ejected from the molds as completed cell elements. It is typical to have combinations of cell elements to be completed on each cycle of the COS machine; depending on the equipment design and battery design, this may be enough elements for several batteries from each machine cycle.

The fused cell elements are next placed into the battery container openings in the proper arrangement for the specific battery design. The cells must be arranged such that a series connection can be made from cell-to-cell – positive straps to negative straps (or vice versa) until all cells in the battery are connected. Over the years, various techniques have been developed for this cell connecting process – either up-and-over the cell partitions or more recently, Through The cell Partitions (TTP). In most modern production plants this connection is now accomplished by resistance welding the element straps though a hole that has been previously punched in the container intercell partition walls (TTP Welding Process).

The next assembly process normally involves sealing a cover to the top of the container that is housing the fused and interconnected plate elements. While, depending on the materials used this sealing process can be performed with various techniques, in most present day designs this process is now a heat-sealing process performed on plastic containers and covers.

And finally, the last basic assembly step is to weld the terminal posts in the negative and positive terminal cells to the respective cover bushings, thereby forming the final electrical connections, as well as, the last acid-tight sealing step.

During the previously described assembly steps, many quality process checks are visually and/or automatically performed to assure that the final assembled battery is free from defects. Typical tests include: high potential short testing, reverse element testing, continuity testing, TTP weld monitoring and/or audit testing, container-to-cover leak testing, etc.

FORMATION PROCESS – CHARGED AND WET BATTERIESThe battery is now structurally complete, and the plates are ready to be "formed" into lead dioxide (PbO2) positive plates and sponge lead (Pb) negative plates. This is accomplished by filling the battery with sulfuric acid electrolyte and charging it until the plates are fully "formed." If the electrolyte strength at the end of formation is lower than that used in service, the low specific gravity acid is then drained from the battery and the battery is refilled with a higher concentration to give the desired final specific gravity sulfuric acid. The dump and refill process may be followed by a short finishing charge to enhance acid mixing.

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Following appropriate tests, the battery is ready to be shipped.

Manufacturers will use from six to as high as forty hours or more to form a battery. The formation current is chosen at various stages of the formation to keep battery temperatures below acceptable maximums. High temperatures can be reduced by the use of external cooling during formation (fans and/or cooling water) and sometimes even chilled forming acid. This allows higher charging currents and reduced formation times.

VRLA BATTERIESAGM batteries are normally formed by adding a fixed amount of electrolyte to each cell that is slightly more than the amount needed in service. After the formation is complete, the battery is sealed with a pressurized valve or valves to promote recombination and prevent oxygen from entering the battery.

Gel batteries are somewhat more complicated. Gelled electrolyte that is normally made with the addition of silica requires agitation to remain fluid so that it can be added to a battery. Once it is added to a drained battery, the electrolyte sets to a gelled state. Gel batteries also require a pressurized valve regulated vent.

DRY CHARGED BATTERIESThe process for making a "dry charged" battery is similar to the above described methods. Elements can be formed separately, washed, dried and inserted into cases before the battery is sealed. Plates can also be formed in large tanks after which they are washed and totally dried before assembly. When the battery is placed in service, it must be "activated" (filled with electrolyte) and given a boost charge. The advantage of dry charged batteries is that they can be held in stock for long periods of time without degradation or having to be boost charged.

DAMP-DRY BATTERIESTo reduce shipping weight "damp-dry" batteries are basically made as described for charged and wet production batteries above except most of the electrolyte is drained and removed from the battery after the forming process. After the battery is drained, the cell vents are substantially sealed and the battery is shipped. Additives are typically put into the residual electrolyte to prevent shorting reactions when the acid gets completely consumed by self-discharge during stand. These batteries must also be "activated" and then boosted before being placed in service. These batteries have the advantage of very fast activation in comparison with dry charged batteries because the internal components are already wetted. Unlike dry charged batteries, however, there are still corrosion processes that occur during stand that limit shelf life.

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Chapter 6 STARTING BATTERIES

DESCRIPTION Starting batteries, also referred to as SLI (Starting, Lighting and Ignition) batteries, provide starting power and reserve energy for a vehicle. Starting batteries are produced in a number of different configurations. Wet or flooded batteries contain free-flowing liquid electrolyte. Most are now designed to be used without maintenance, but some still require periodic additions of water to make up for gassing losses. There are also VRLA starting batteries that are designed to recombine charging gasses, which primarily use the AGM design to deliver high cranking power.

Maintenance has been reduced or eliminated by lowering the water loss rate of the batteries. A low water loss battery, as the name implies, is designed to relieve the consumer of routine maintenance requirements such as watering during the service life of the battery. Most types of low water loss batteries produce very little gas at normal charging voltages and, therefore, the rate of water loss is very low. When properly charged, water additions are not necessary for the life of the battery.

Reduced water loss has been achieved primarily through improvements in the grid alloys. In older technology battery grids, antimony was used as an alloying metal to enhance castability and hardness of lead. However, higher concentrations of antimony in the grid alloy yielded greater rates of water loss and self-discharge.

The grids of low water loss batteries contain little or no antimony. Other metals such as calcium are substituted for antimony in order to provide the necessary mechanical strength, while reducing gassing and self-discharge.

Additional advantages of low water loss batteries when compared to older technology wet batteries include: 1) the elimination of activation and boost-charging prior to installation, 2) greater overcharge resistance, 3) reduced terminal corrosion, 4) longer shelf life and, 5) the elimination of overfilling and the attendant possible addition of harmful impurities.

TESTING STARTING BATTERIES.Before conducting any battery tests, refer to Chapter 2 for a review of all safety precautions.

Battery testing should be considered an integral part of periodic vehicle maintenance and should be performed whether or not a starting problem has occurred. Servicing the battery in the vehicle as described in Chapter 12 will help prevent premature battery failure from external causes.

There are a variety of battery testers, hydrometers, and voltmeters available for testing all types of batteries. The proper equipment should be used when conducting a test. This section deals with testing lead acid batteries that have been used in starting, lighting, and ignition (SLI) applications.

For information regarding the testing of electric vehicle batteries, refer to Chapter 7. For tests that are used to determine the performance of new batteries, refer to the BCI Technical Manual.

The standard method of testing a battery that has been in service is the adjustable load test that applies a load of the CCA (Cold Cranking Amperes) rating of the battery for 15 seconds.

TESTING WITH AN ADJUSTABLE LOAD TESTERWhen testing batteries with an adjustable load tester, refer to the “Starting Battery Load Testing Chart” at the end of this chapter.

Step 1 — Visual InspectionVisually inspect the battery for container, cover or terminal damage that may have caused leakage of electrolyte or internal damage. If serious damage is found, replace the battery. Proceed to Step 2.

Step 2— Electrolyte Levels and State of ChargeElectrolyte Levels

Although wet starting batteries are normally designed to preclude the need to add water, the volume of reserve electrolyte above the plates may eventually be depleted. In most cases, this will signal the end of the battery's useful life. Since many have sealed covers in place of filler caps, it may not be possible to check the electrolyte levels by looking directly into the cells. However, many low water loss batteries are contained in translucent plastic cases that may allow electrolyte levels to be seen. Other models utilize built-in hydrometers that also serve as electrolyte level indicators. If electrolyte levels can be seen and are found to be low, check for a charging system malfunction.

If vents are removable, check the electrolyte level in each cell. If the electrolyte level is below the tops of the plates in any cell, add water before proceeding further if vents are removable. If water cannot be added, replace the battery. If water is added, the battery should be charged fully before proceeding with other testing.

There is no free electrolyte in a VRLA battery. No effort should be made to test or adjust its electrolyte level.

For best results on the Adjustable Load Test, the battery should be fully charged. The battery must be at an adequate state of charge in order for the following load test procedure to be valid. The state-of-charge can be estimated with an accurate voltmeter or hydrometer.

22

If the state-of-charge of a battery is too low or cannot be determined by voltage or specific gravity (see below), it must be charged fully. (See Chapter 13.)

Specific Gravity

If the electrolyte is accessible, the state of charge can often be estimated by the measurement of the specific gravity of the electrolyte. The correct procedure for using a battery hydrometer is described in Chapter 3. Use the hydrometer to measure the specific gravity, corrected to 80°F (26.6°C), of each cell; record the readings.

If the range (highest to lowest reading) is 50 points (0.050 sp. gr.) or more, or the lowest reading is less than 1.260 specific gravity, charge the battery fully. Continue charging until all cells are 1.260 specific gravity or greater and the range is less than 50 points. If charging will not achieve these conditions, replace the battery.

If the specific gravity is above 1.260 and shows no low specific gravity cells indicating shorting, proceed to step 3 (Adjustable Load Test).

Be aware that often the electrolyte specific gravity may register as low because of stratification, especially in low water loss batteries that reduce the gassing necessary to mix the electrolyte with charging.

Open Circuit Voltage

The state of charge of a battery can also be estimated by measuring the stabilized voltage of the battery. The voltage is considered to be stabilized if the battery has been on open circuit for a minimum of four hours. A voltage reading of 12.6 (6.3 on a 6-volt battery), the equivalent to a specific gravity of 1.260, should be the minimum voltage suitable for load testing.

If the stabilized open circuit voltage is below 12.6 volts, charge the battery as described in Chapter 13. After the battery is charged and the stabilized voltage of the battery is 12.6 or above, proceed to Step 3 (Adjustable Load Test).

Step 3 — Adjustable Load TestFor tests conducted with an adjustable load tester, refer to the figure “Starting Battery Load Testing Chart” at the end of this chapter. The following instructions are intended to be guidelines. Follow the manufacturer’s instructions when conducting a load test.

Be sure the terminals are free of corrosion.

Connect the voltmeter and load test leads to the battery terminals; be sure the load switch is in the "OFF" position. Apply a load test equal to 1/2 of the Cold Cranking rating of the battery at 0°F (-17.8°C). Read the voltage after 15 seconds with load connected. Remove load. Estimate or measure battery temperature and compare voltage reading with the "Adjustable Load Test Voltage Chart". If the voltage meets or exceeds the specified minimum, return it to service.

If the battery fails the load test, the state of charge must be rechecked. The stabilized open circuit voltage can be used to determine the state of charge. Allow at least 10 minutes after the load test for the voltage to stabilize and then measure and record the open circuit voltage. If the voltage is 12.6V or greater and the battery failed the load test, it should be replaced.

If the battery fails and the voltage is below 12.6V, the battery should be charged at the recommended rate and time shown in Chapter 13, and the load test repeated. If it fails the load test again, replace it and refer to Chapter 15 to determine the cause of failure.

ALTERNATE BATTERY TESTERSThere are various battery testers that use fixed or varying heavy amp loads to indicate the battery condition based on a function of the loaded voltage.

In addition there are also testers available that use measurements of conductance or resistance to indicate battery condition. These microprocessor-controlled testers assess the remaining starting power of the battery without applying large current loads. While these testers do not put a heavy load directly on the battery, they do have the advantage of not discharging the battery, minimizing sparking during testing, not requiring the battery be fully charged to make a correct judgment and not requiring trained personnel for operation.

Whatever testing method is chosen, acceptable battery testers should trace the fitness of a battery for further service to the Adjustable Load Test standard.

Step 1 — Visual InspectionFollow the same visual test procedure as indicated in the previous section, “Testing with Adjustable Load Tester.”

Step 2 — Check the Electrolyte LevelIf vents are removable, check the electrolyte level in each cell. If the electrolyte level is below the tops of the plates in any cell, add water before proceeding further if vents are removable. If water cannot be added, replace the battery. If water is added, the battery should be charged fully before proceeding with other testing.

There is no free electrolyte in a VRLA battery. No effort should be made to test or adjust its electrolyte level.

Step 3 — TestingFollow the tester manufacturer’s instructions when conducting a battery test.

The tester should include an input interface to allow the user to choose among a variety of battery sizes on the basis of the battery CCA rating. It may also include a means of correcting for battery temperature, either with an automatic sensing circuit or one that can be set manually.

23

If the battery has insufficient charge to be diagnosed, it should be charged and retested.

If the battery passes the test, it can be returned to service. This may require a recharge if the battery is too discharged.

If the battery fails the test, it should be replaced.

DETERMINING THE CAUSES OF BATTERY FAILURE IN THE VEHICLE

1. Corroded Battery Terminals or ConnectorsA corrosion layer between the battery terminals and the cable connectors can prevent good electrical contact even when the connectors are tight. The cables should always be removed before testing a battery and any corrosion removed from the terminals and cable clamps. Check the condition and size of the battery cables.

Check for corrosion on the battery terminals and cable terminations. Corrosion on side terminal batteries may not be evident until the cables have been removed. Replace badly corroded cables or cables with defective terminations. Make certain the ground cable is making a good connection where it is grounded and likewise, check the connection of the cable to the starter relay and/or solenoid. Perform voltage drop tests as needed on cables and connections. Proceed to Step 2.

2. Electrical Circuit LeakageMost vehicles will normally have a small, continuous discharge on the battery. This discharge (sometimes called a parasitic draw) can range from 20-40 milliamperes or more and is caused by electronic equipment that must be powered continuously or intermittently.

Of course, there may also be a fault in the vehicle’s electrical system that can discharge the battery even when all the accessories are turned off. To check for such leakage, turn off all accessories in the vehicle and close all doors, trunk, etc., in order to turn off all lights and warning systems. If there is a light under the hood, remove the bulb. Many cars have loads that remain on after the ignition is shut off. Fans, computer diagnostics, lights, etc. can often run for a period of time before disconnecting. It must be insured that these vehicle loads do not interfere with the leakage test.

Check for leakage using the following method. Use a Hall effect (inductive) DC ammeter that measures current by placing an amp clamp around the ground cable wire. Using an ammeter with a resolution of at least 0.1 amps, measure the current. A high current indicates that the electrical system may have a short that must be found and repaired.

If a recharged battery fails in service a second time and no vehicle problem can be found, perform the following test. (1) Fully charge the battery, (2) Allow it to sit disconnected from all loads for 72 hours. If the battery will hold a charge when disconnected, but won’t hold a charge in the vehicle, this is another indication that there is excessive electrical system leakage or an intermittent charging system problem.

3. Vehicle Charging SystemTo complete the determination of the cause for the battery’s discharged condition, check the vehicle’s charging system as described in Chapter 16.

24

Starting Battery Load Testing Chart

STEP 1

STEP 2

STEP 3

VISUAL INSPECTION

Check for damage, leaks, etc.

Replace Unusable? Proceed to Step 2

Check Electrolyte Level(Wet Batteries)

Below top of plates ?or

Built-in hydrometer eye clear orlight yellow?

Replace

Determine Charge Level

Add Water

Stabilized Voltage < 12.6or Sp.Gr. < 1.260?

Charge the batteryand stand to

stabilize

Proceed to Step 3

Connect Load Tester with Voltmeter to the battery

Discharge for 15 seconds at 1/2 the CCA rate

15 sec V >=chart value?

Replace

Return to Service

Estimated ElectrolyteTemperature - deg F

Minimum acceptablevoltage at 15 seconds

120 10.1110 10.0100 9.990 9.880 9.770 9.660 9.550 9.440 9.330 9.120 8.910 8.70 8.5

Adjustable Load Test Voltage Chart

Yes No

Can water beadded?

Yes

No

YesNo

YesNo

No

Yes

Load Test

Recovery Voltage (10')< 12.6?

No

Yes

Shorting Indicated?(Sp.Gr. range > 50 pts)

Replace

Yes

No

VRLA

Determine battery temperature

25

Starting BatteryAlternate Battery Tester Chart

STEP 1

STEP 2

STEP 3

VISUAL INSPECTION

Check for damage, leaks, etc.

Replace Unusable? Proceed to Step 2

Check Electrolyte Level

Below top of plates ?or

Built-in hydrometer eye clear or lightyellow?

Replace Add WaterCharge the battery and

stand to stabilizeProceed to Step 3

Connect tester to the battery

Follow the testing menu procedure to get adecision

Charge andRetest?

Replace Return to Service

Yes No

Can water be added?

Yes

No

YesNo

Yes

Alternate Battery Test

Good?

No

No

Yes Requires Charge?

Charge andReturn to Service

No

Yes

VRLA

26

Chapter 7 GOLF CAR, DEEP CYCLE MARINE AND OTHER CYCLING

BATTERIES

DESCRIPTIONThis chapter will discuss the type of cycling batteries used in golf cars, neighborhood electric vehicles, personnel carriers, electric vehicles built for highway use as well as in floor sweepers, high lifts and marine deep cycle batteries.

A cycling battery has a service requirement that is quite different from that of an automotive battery. The automotive battery must deliver high cranking currents at a satisfactory voltage for a few seconds and a portion of the accessory load (10-25 amperes) for a minute or two at a time in city or heavy traffic. Therefore, the automotive battery is designed with maximum plate area and low internal resistance to provide high cranking performance. Power taken from this battery is immediately replaced by the alternator or generator. Therefore, the battery is subjected to shallow discharge cycles (2-3% of the battery capacity). These batteries normally operate in a high state of charge range.

Cycling batteries supply the motive power and power for the accessories for the vehicles in which they are used. The rate of discharge varies with the type of service. In golf car service, depending on the system voltage, the battery normally receives a nominal intermittent discharge of 56 or 75 amperes over a range of 20-250 amperes. Cycling batteries in other applications may be asked to deliver several times this amount. The depth of discharge varies with the length of time the battery is used before being recharged. Once the battery is discharged, it must be recharged to continue operating the vehicle since it is not maintained by a vehicle generator or alternator. These batteries usually receive "deep" discharges (50-80% or more of their capacity).

Cycling batteries are designed to have good life performance in "deep" cycle service. The major cause of battery failure in "deep" cycle service is shedding or softening and loosening of the active material from the positive grids. It is for this reason that cycling batteries have design features such as high density plate material and fibers in the active plate material, to retard the loss of active material from the grids. Most battery manufacturers also use separators with fiberglass mats that face the positive plates to minimize this shedding.

Cycling batteries have traditionally been flooded designs with positive grids containing antimony alloys to promote cycling. There are also VRLA designs that provide enhanced cycling performance and that do not require watering.

TESTINGCaution: The safety practices recommended for automotive batteries (see "Safety Precautions", Chapter 2) should be followed when testing or charging cycling batteries. In addition, higher voltage packs of batteries may present an electrocution hazard. This hazard may be greatly increased when charging.

Only properly trained personnel should attempt to service high voltage battery packs. Troubleshooting, safety and servicing instructions found in the application owners manual or service manuals should be followed where they differ from this guide.

If a vehicle is not performing satisfactorily, and it is suspected to be battery related, test the battery or each battery in a set of batteries for the cause.

Ensure that the problem is not in the charger, the motor/controller or in the inter-battery connections. (See the diagnostic chart Figure 7-1.)

Connections between the batteries and the vehicle that show signs of corrosion (white deposits) are usually the results of electrolyte flowing out of the cells due to over watering or spewing. This corrosion prevents the batteries from delivering full power. If corrosion is present, ENSURE ALL VEHICLE SWITCHES ARE TURNED OFF before the connections are removed and the acid and corrosion neutralized. Battery posts and cable lugs should then be wire-brushed to shiny metal before reattaching. Rinse posts and cable lugs with clear water and ensure vent caps are installed tightly in place.

HYDROMETER CHECKSee "Hydrometer - Description and How To Use", in Chapter 3. If possible, measure the specific gravity of the electrolyte in each cell of each battery. If the variation between the highest and lowest cell readings in any one battery is 0.050 (50 gravity points) or more, the cell(s) with the lowest reading may be suspect. This can be verified by conducting a load test. Do not load test discharged batteries.

NOTE: If the cells have been overfilled frequently due to carelessness in adding water, there will be a gradual drop in specific gravity. This could create a 0.050 variation without an internal-mechanical problem. If water has just been added, several additional cycles may be required to mix the electrolyte and ensure a reliable measurement.

VOLTMETER CHECKIf the top connectors are accessible, read the voltage of each cell. A variation between the highest and lowest cell readings of any one battery of 0.05 volts or more indicates a possible failing cell.

If the voltage of each cell cannot be measured, test the terminal voltage of each battery if a set of batteries is being checked. Compare the voltage of the batteries. If the battery voltage readings vary by 0.05 volts or more, there is probably a weak or failing battery.

If the batteries in the vehicle have been on charge, and are to be tested with a voltmeter, drive the vehicle around for

27

approximately 30 seconds, then let it stand idle for three or more minutes before testing. This procedure stabilizes the voltage in that it removes a charge polarization from the plates that would otherwise give a false high voltage reading.

LOAD TESTThis is the most accurate test and designed to simulate the demands imposed on the batteries supplying power to electric vehicles.

Fully charged batteries are discharged at the constant rate specified for the type battery being tested to a terminal voltage equivalent to 1.75 or 1.70 volts per cell depending on type of deep cycle battery. The product of time versus amperes will be the Ampere-Hour capacity of the battery. If the electrolyte temperature differs from 80°F (26.7°C), expectations must be adjusted.

Golf car batteries should be tested as indicated above at a rate specified by the manufacturer, typically 75 amperes for 6-volt batteries and 56 amperes for 8-volt or 12-volt batteries. There are load testers on the market capable of testing batteries in the vehicle. If the hydrometer or voltmeter check indicates a battery, or one battery in a set of batteries, is failing, fully charge it and conduct the load test. Record the discharge time in minutes it took for the cell voltage to reach 1.75 volts per cell (5.25 volts for a 6-volt battery; 7.0 volts for an 8-volt battery; 10.5 volts for a 12-volt battery). A battery that delivers 50% or less of its rated capacity in minutes should be replaced.

The life of a cycling battery is determined not only by the number of cycles (a discharge and a recharge) it receives, but also by the depth of each cycle. If a set of batteries is used to operate a golf car for 18 holes per day, this equates to approximately one life cycle. If they are used for 36 holes, this is a much deeper discharge and is equivalent to approximately three life cycles. A battery pack used 36 holes per day has a life span approximately one-third that of one used for 18 holes per day.

CHARGINGFollow the safety precautions listed for automotive batteries under "Safety Precautions", "Charging a Battery". The manufacturer's instructions must be followed whenever a charger is used.

The charging area must be well ventilated. Make certain to follow charger manufacturer instructions for proper cable removal. Never touch the charger leads while the charger is "ON".

A cycling battery should be fully charged every day it is used, even if it is only discharged 25%. Do not completely discharge a battery if it can be avoided. As mentioned previously, the deeper the discharge, the less life you will ultimately obtain from the battery. If the batteries are being used more than normal, it is recommended that they be placed on charge for an hour or two during the day (at lunch time for example). This procedure will reduce the depth of discharge and prolong battery life. If the vehicle is not used during the work period, do not place the batteries on charge. Overcharging batteries also shortens their lives.

The amount of recharge a battery needs can be determined by measuring the specific gravity with a hydrometer. The chart below shows the approximate "percent charged" of a cycling battery, at various specific gravity values, corrected to 80°F (26.7°C).

Most users of cycling batteries have purchased automatic chargers for recharging their batteries. This equipment is designed to put back the charge that was taken out of the battery by sensing the battery voltage and turning the charger off when the battery reaches a fully charged state. The charging rate starts high and tapers to a low "finish" rate automatically.

APPROXIMATE STATE OF CHARGE

1.300 INITIAL 1.280 INITIAL 1.265 INITIAL CHARGED FULL CHARGE FULL CHARGE FULL CHARGE

100% 1.300 1.280 1.265

75% 1.255 1.240 1.225

50% 1.215 1.200 1.190

25% 1.180 1.170 1.155

DISCHARGED 1.160 1.140 1.120

28

It is important to match the charger to the battery pack. Full charge should be verified with hydrometer readings taken after charge. If the full charge specific gravity is not reached, repeated cycling under these conditions will shorten battery life. If this occurs, contact the manufacturer. It is also recommended that a monthly equalizing charge of 3-4 hours additional charge be given following the full charge, especially if variation in specific gravity of the electrolyte among the cells is greater than 0.010 or less than the manufacturer's specified full charge specific gravity. Newer chargers may incorporate an automatic equalize mode.

If the electrolyte level is low, add water near the end of charge or after taking the battery off charge. Never allow the electrolyte level to drop below the tops of the plates because the exposed portion of the plates will become permanently inactive due to sulfation.

Never overfill a battery cell above the level indicator or it will pump acid when it is placed on charge. This reduces the capacity of the battery and corrodes metal parts near it. If the electrolyte level is below the tops of the plates, add only enough water to cover them before charging. Overfilling a discharged battery with water can easily result in an overflow of electrolyte from the cells. Add water, if necessary, to bring electrolyte level to the level indicator after charging, or near end of charge.

Cycling batteries should be fully charged, clean, and dry if they are to be stored for any length of time. Store in an unheated, dry area. Check the specific gravity of the electrolyte periodically with a hydrometer or boost charge every three months. If the specific gravity is being checked, recharge the battery when it reaches 1.220. The time it takes the battery to reach 1.220 specific gravity depends on its condition and the temperature of the environment in which it is stored. The colder the storage area, the slower the battery will self-discharge. The normal period before a recharge is required is three months.

CAUTION: New cycling batteries do not have their full capacity until they have been cycled several times (usually between 20 and 150 cycles). Therefore, they can be excessively discharged early in their vehicular life, thereby shortening their service life. It is recommended to limit operation of new vehicles, or older vehicles with new batteries, to well below their advertised range for at least the first 20 cycles and then gradually increase the range.

It is highly recommended that batteries in a string be of the same age. Replacing one battery in an older string with a new battery can cause the charge voltages of the batteries in the string to become out of balance causing charge problems.

29

Step 1: Visual Inspection of Batteries and VehicleBatteries defective--broken post, broken case, broken cover--repair or replace.Cables defective--cracked insulation, corroded metal, loose crimps, etc.--repair or replace.

Step 2: Check OCV's (Open Circuit Voltages)Recently charging batteries will have elevated OCV's from "surface charge".

6-volt 8-volt 12-volt3 cells 4 cells 6 cells6.3 or more

8.4 or more

12.6 or more

5.8 to 6.2 7.7 to 8.311.6 to 12.5

5.7 or less 7.6 or less11.5 or

less

3.9 to 4.3 6.0 to 6.410.2 to 10.6

Step 3: Charging TestOnly batteries of matching capacities with similar voltages and ages should be charged inseries. Connect to appropriate charger. Observe initial current and current after 15 minutes.Connections between batteries can be tested for excessive voltage drop with a sensitive voltmeter. While charging at 20 amps, the voltage from the positive post of one battery to thenegative post of the next battery should be less than 0.010 volts (10mV).

InitialCurrent

15-minuteCurrent

Over 25 Over 10

Over 15 Under 5

Step 4: Discharge Test

6-volt 8-volt 12-volt3 cells 4 cells 6 cells

5.95 7.90 11.90 1.255 to 1.285

5.60 7.45 11.20 1.195 to 1.225

5.20 6.90 10.40 1.135 to 1.165

Charged, ready for discharge test--unless affected by surface charge. Check and adjust electrolyte levels.

Probably only discharged. Check and adjust electrolyte levels. Recharge.

Possible defective cell and/or low electrolyte levels. Check and adjust electrolyte levels. Recharge.

Typical voltage of battery with one shorted cell. Replace battery. (If all batteries in the pack match, may be a coincidence. Check and adjust

electrolyte levels. Recharge.)

Run the golf car or use a discharge tester. Use a 75-amp discharge for 36-volt systems. Use a 56-amp discharge for 48-volt systems. Golf courses may vary. Monitor the voltage under load. Cold temperatures reduce range, runtime and voltage under load.

Golf Car Deep Cycle Marine and Other Cycling Battery Diagnosis Chart

Specific Gravity Adjusted to 80oF

Batteries are fully charged. Ready for discharge test. (Older batteries may have higher end of charge current.)

Check charger and circuits.No Reading

Interpretation/Disposition

Batteries are discharged. Recharge fully before discharge testing.

Battery pack considerations: Differences between batteries from the same pack are informative. Larger differences point towards failing batteries. The closer the voltages are, the more likely that low voltage is a result of discharging.

Interpretation/Disposition

After 18 holes of golf or 40minutes of loadAfter 36 holes of golf or 80minutes of load

Beginning of use or discharge

Normal (Healthy) Readings

30

Chapter 8 BATTERY RATINGS

Batteries used in automotive and commercial applications are rated in accordance with the COLD CRANKING PERFORMANCE and RESERVE CAPACITY ratings. These ratings are described below.

Performance testing of batteries is a laboratory procedure that is outlined in the BCI Technical Manual. These procedures, when followed closely, will furnish precise data on the Cold Cranking and Reserve Capacity ratings of a battery.

Also described in the Technical Manual are procedures for testing dry charge activation, charge rate acceptance, vibration resistance, cycle life, and a gassing test that describes a battery's ability to maintain its reserve of water in the electrolyte.

COLD CRANKING PERFORMANCEThe basic job of a battery is to start an engine; it must "crank", or rotate the crankshaft while at the same time maintain sufficient voltage to activate the ignition system until the engine fires and maintains rotation (runs). This requirement involves a high discharge rate in amperes for a short period of time.

Since it is more difficult for a battery to deliver power when it is cold, and since the engine requires more power to turn over when it is cold, the Cold Cranking rating is defined as:

The discharge load in amperes that a new, fully charged battery at 0°F (-17.8°C) can continuously deliver for 30 seconds and maintain a terminal voltage equal to or greater than 1.20 volts per cell.

This discharge load or "Cold Cranking Amps", often abbreviated "CCA's", generally falls within the range of 300 to 900 amperes for passenger car applications and higher for commercial vehicles. It should be emphasized that this test is only meant to generate and determine compliance of new batteries to their ratings.

RESERVE CAPACITYReserve Capacity is a comparative measure of the ability of a battery to sustain a minimum system voltage under load in the event of a charging system failure.

It is also a comparative measure of the battery's ability to provide power for vehicles having small parasitic electrical loads with the engine off for long periods and still have enough capacity to crank the engine. The Reserve Capacity rating is defined as:

The number of minutes that a new, fully charged battery at 80°F (26.7°C) can be continuously discharged at 25 amperes and maintain a terminal voltage equal to or greater than 1.75 volts per cell.

EFFECTS OF TEMPERATURE AND CHARGE LEVEL OF BATTERY PERFORMANCEBattery performance is greatly reduced by lower temperatures because the electrolyte resistance climbs, the diffusion of reactants and products is slowed, and solubilities are reduced as temperature drops.

The combined effect of 0°F (-17.8°C) in reducing battery capacity and the increase in cranking load due to stiff oil to as much as twice the warm weather load, gives us an appreciation of the job a battery has to do in cold weather. This emphasizes the need to keep the battery fully charged.

A nearly-discharged battery at 0°F (-17.8°C) has a considerable amount less than the available cold cranking ability of a fully charged battery at 80°F (26.7°C). Once again, this emphasizes the importance of keeping batteries fully charged, and to recommend a recharge when the gravity falls to 1.225 or lower. A battery discharged to 1.140 Sp. Gr. or less cannot be expected to crank an engine at any temperature.

A battery discharged at a lower rate, corresponding to a load such as the Reserve Capacity rate, would be considered "half-discharged" at 1.225 Sp. Gr. and "discharged" at 1.140 Sp. Gr. at 80°F (26.7°C) based upon a full charge specific gravity of 1.275.

Note: Some manufacturers use different fully charged specific gravities. For the full charge specific gravity of a particular battery, consult the manufacturer.

31

Chapter 9 RECEIVING NEW BATTERY SHIPMENTS

SHIPPING CONDITIONFollowing are four conditions under which automotive batteries may be shipped:

Description of Condition for Shipping

Plates Charged or Uncharged

Condition of Plates & Separators When Shipped Cells Filled or Unfilled

Wet-Charged Charged Wet Filled

Dry-Charged Charged Dry Unfilled

VRLA Charged Wet, absorbed or gelled electrolyte Filled

Damp - Dry Charged Wet Unfilled

INSPECT SHIPMENT FOR DAMAGEImmediately upon receipt of new batteries, check electrolyte levels (if possible) to determine possible liquid loss during shipment. In the case of dry-charged batteries, only visible damage can be considered since there is no electrolyte present in the batteries. Inspect incoming batteries for mechanical damage, either visible or concealed, which may have occurred during shipping. "Concealed damage" is understood to mean damage to the contents of a package, which is not evident at the time of delivery by the carrier but which is later discovered.

The carrier is responsible for batteries lost or damaged in transit. The title to goods rests with the consignee when batteries are shipped F.O.B. factory, and only the consignee can legally file claims. When loss or damage is noted at the time of delivery, require the person receiving the delivery to note loss or damage on "delivery receipt" copy of the freight bill or obtain his or her signature under the consignee's statement of loss or damage on the same document. He or she should contact their office and report any lost or damaged product. Submit claim by presenting to carrier who made delivery, the following information:

1. Standard form for presentation of loss and damage claim.

2. Original bill of lading.

3. Original or certified copy of invoice.

4. Original paid freight bill with signed notation of loss or damage.

When loss or damage is discovered after delivery:

1. Segregate damaged batteries, cartons or crates.

2. Immediately request carrier to make an inspection and confirm request with a letter. If inspection is waived, obtain a written "waiver."

3. If inspection is not made by carrier within five days, make your own inspection report. If possible, use form "Inspection Report of Loss or Damage Discovered after Delivery of Freight."

4. Submit claim by presenting all four items listed above under the section headed “When the loss or damage is noted at time of delivery" and in addition submit "Carrier's Inspection Report", or "Waiver" or your request for inspection and your report on your own inspection.

If no acknowledgment of claim is received within thirty days, request one by letter. If no settlement is made within sixty days, review the claim for a decision regarding necessary action, legal or otherwise. Two years are allowed in which to file suit after a claim is disallowed in writing by the carrier.

Shipments of damaged battery must be in compliance with the U.S. hazardous materials regulations. The regulations authorize the use of salvage drums for packages of hazardous materials that are "damaged, defective, or leaking." Therefore, damaged batteries may be placed in a compatible metal or plastic removable head salvage drum. The drum must be a UN 1A2, 1B2, 1N2 or 1H2 tested and marked for Packing Group III or higher performance standards and a leakproofness test of 20 kPa (3 psig). Capacity of the drums may not exceed 450 L (119 gallons). Each drum shall be provided, when necessary, with sufficient cushioning and absorption material to prevent excessive shifting of the damaged batteries and to eliminate the presence of any free liquid at the time the salvage drum is closed. All cushioning and absorbent material used in the drum must be compatible with the batteries. If applicable, each salvage packaging must be marked and labeled in accordance with the regulations. In addition, the packaging must be marked "SALVAGE" or "SALVAGE DRUM." Shipments also may be subject to proper shipping paper requirements. For more information, see 49 CFR 173.3 of the U.S. hazardous materials regulations.

32

Chapter 10 BATTERY STOCK MAINTENANCE

The following general instructions apply to all types of batteries whether they are wet, dry charged, damp-dry or VRLA construction.

A responsible service person should be given the responsibility of the battery room and inventory maintenance. Duties, and the appropriate safety procedures, should be clearly explained. The proper tools and equipment should be provided and an understanding of their use should be required.

Equipment should include a slow charger, a fast charger, battery connectors, hydrometers, and thermometers. A carrying strap, terminal cleaner, water filler and a supply of baking soda for the neutralization of acid should also be available.

The battery charging room, or area, must have adequate ventilation. The required rate of air exchange depends on the maximum charging rates and maximum number of batteries that may be charged at one time. An exhaust fan may be needed. Consult local building, fire and regulatory authorities for applicable requirements. Safety equipment such as eye protection, rubber gloves, safety shoes, acid proof clothing, etc., should be provided. An eyewash sink should also be available in case of emergencies.

All batteries should be stored in a cool, dry place in an upright position.

STOCK ROTATION

Battery stock must be rotated on a strict, first-in, first-out basis. This rule is important regardless if the battery is wet, dry charged, damp-dry or VRLA construction. Date codes should be stamped on the cartons and the batteries to accomplish this important rotation rule. The main cause for selling a dated, discharged replacement battery, is failure to follow the "first-in, first-out" rotation rule.

STORAGE

Roller racks provide the best method for storing and insuring the proper rotation of batteries. Racks should be marked on the front and rear so the same type of battery will go in the same rack every time. If racks are loaded properly, the oldest battery of a particular type will always appear in the front.

If roller racks are not available, wooden shelving can be used. Stock rotation is difficult using this type of storage, unless the shelving can be simultaneously accessed from the front and the rear. If the shelving cannot be accessed from the front and rear, rotation will have to be done by hand. Try to store batteries of the same type, with approximately the same date codes on the same shelf. Never mix types.

Batteries should never be piled one on top of the other. Simple racks for temporary battery storage can be made from loose, flat boards. No nails are required. All boards should be cut from 3/4" (19mm) thick stock. Uprights may be 10" (254mm) high and about 12" (305mm) wide. Shelf boards can be 4" (102mm) wide and 38" (965mm) long. Eight uprights and 10 shelf boards will permit stacking 25 batteries, 5 batteries per row, and 5 tiers high. See Figure 10-1.

The stack is built as follows: Lay parallel, on a smooth, flat floor, two shelf boards spaced so that the bottom of the batteries are supported by them. Place 5 batteries side by side in a row and insert one upright between the first and second battery, and one between the fourth and last. Push the batteries snugly together to support the upright pieces. This type of rack is for compact, temporary storage. Continue this stacking procedure; the finished storage rack will look like Figure 10-1.

Figure 10-1: Storage Rack

WET BATTERIES

Check batteries before placing them in storage to make certain they are fully charged. If a battery becomes severely discharged, the electrolyte can freeze if it is stored below +20°F (-7°C). To prevent damage due to freezing, do not allow batteries to become discharged or to be stored below +20°F (-7°C).

Figure 3-5 graphically shows the electrolyte freezing points at specific gravities from 1.100 to 1.300. These values are the approximate temperatures at which ice crystals begin to form. The electrolyte does not freeze solid until a lower temperature is reached. Solid freezing of electrolyte in a discharged

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battery may damage the plates and may crack the container. Under most conditions, the electrolyte will not freeze solid and there will be no damage to the battery.

A battery that is at a 75% state of charge, or greater, is in no danger of freezing. Therefore, batteries should be kept at least 75% charged, especially during the winter. The state-of-charge of stored batteries should be checked every 30 days.

SELF-DISCHARGEAll automotive wet batteries will slowly lose charge when not in service. This is known as self-discharge.

Low water loss batteries containing very little or no antimony in the grid alloy, self-discharge at a lower rate than conventional batteries. The rate of self-discharge increases with increasing temperature; this is true for both conventional and low water loss batteries. Figures 10-2 and 10-3 illustrate the effect of storage temperature on self-discharge.

Allowing batteries to stand for an extended period without recharging them will result in reduced performance and service life. To preserve optimum battery performance and life, recharge batteries in storage when the open circuit voltage drops to 12.4 volts.

If live batteries are used for display purposes, don’t forget to boost and rotate these batteries as needed. Many manufacturers can supply “dummy” batteries containing no active materials for display purposes.

Figure 10-2: Effect of Storage Temperatures on Self-Discharge – Typical Low Water Loss Batteries

Note: Figures 10-2 and 10-3 assume a fully charged specific gravity of 1.265, which yields a fully charged open circuit voltage of 12.65. Many battery designs use higher fully charged specific gravities. For the full charge specific gravity and open circuit voltage of a particular battery, consult the manufacturer.

Figure 10-3: Effect of Storage Temperature on Self-Discharge – Typical Conventional Batteries

CHARGINGIf a battery is not sold or put into service before its voltage falls to 12.4, it should be charged fully. The voltage should not be allowed to decline further. Proper charging varies between battery types. Reference Chapter 13 for general charging instructions. For valve-regulated batteries refer to the Charging Considerations section in Chapter 16. For golf-car and other deep-cycle batteries that are not valve regulated, refer to Chapter 7.

DRY CHARGED AND DAMP-DRY BATTERIESDry charged batteries contain no electrolyte until activated for service. Damp-Dry batteries have plates and separators moist with electrolyte but are nearly empty until activated. These batteries should be stored in a cool, dry place. The ambient temperature should be as uniform as possible. Large temperature fluctuations will cause air to enter batteries as they cool (although they are sealed) and expel air as they become warm. Every time air enters a battery, it will bring moisture and oxygen to the negative plate active materials and adversely affect them. Sealing the cells minimizes this action.

The main advantage of dry-charged batteries is that they can be stored for long periods with minimal deterioration. It is still important to rotate the stock on a "first-in, first-out" basis. The length of time these batteries can be stored depends upon the original processing of the plates and separators, the exposure to temperature variations, and the humidity conditions during storage. Given proper storage conditions, a dry-charged battery will still activate successfully after many years.

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Chapter 11 NEW BATTERY INSTALLATION

BATTERY SERVICING TOOLS

Use proper tools when performing battery service in order to prevent damage to battery, cables, terminals and hold-downs; proper tools will also save time and energy.

Following are suggested battery tools and how they should be used.

Filling Devices

Most batteries used in starting now require no water additions during their service life. However, some batteries may still require periodic water additions to maintain the correct electrolyte level. Two devices are available for this purpose; one is a self-leveling filler (see Figure 11-1), which fills the

Figure 11-1: Self-leveling filler

battery to a predetermined level automatically, and the second is a syringe type (see Figure 11-2). Battery cells should never be filled above the level indicator. When using a syringe, do not squeeze it to the point that the water splashes acid from the cell opening.

Figure 11-2: Syringe filler

Wrenches Cable clamp nuts and side terminal connections should be removed and tightened with the proper size wrench. They should be tightened to the manufacturer’s specified torque to assure a secure connection. The torque values in listed at the end of this chapter may be used as a guide if the manufacturer’s values are not available.

Avoid subjecting the battery terminals to excessive lateral or twisting forces. These forces can damage internal components of the battery and create leakage at the terminals. (See “Installation” at the end of this chapter.)

Cable Clamp Puller (Tapered Terminal Posts)

The cable puller should be used to remove a cable clamp from the battery terminal after the clamp nut has been loosened (see Figure 11-3). The jaws of the cable clamp puller grip the underside of the cable clamp, and the clamp is pulled up by exerting pressure to the top of the battery post. This procedure will prevent damage caused by lateral or twisting forces.

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Figure 11-3 Cable Clamp Puller

Cable Clamp Spreader

The cable clamp spreader (see Figure 11-4) is used to expand cable clamps after they have been removed from the terminals and the clamp bolts have been loosened. It should only be used on lead die-cast terminals. The cable clamps can then be placed on the terminals in their correct positions without force.

Figure 11-4: Cable Clamp Spreader

Tapered Terminal and Cable Clamp Cleaning Brush

This brush is designed to clean tapered battery terminals and the mating surfaces of lead die-cast cable clamps. Wire brushes should not be used on stamped-metal cable clamps since they may wear away the clamps’ corrosion resistant surface. A non-abrasive brush may be used.

Figure 11-6: Terminal Cleaning Brush

Figure 11-5: Cable Clamp Cleaning Brush

Scraper and Wire Brush

A scraper and wire brush can be used to remove dirt, corrosion and rust from the metal portions of the battery tray, the hold down, and the hold down bolts.

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Figure 11-7: Wire brushes and scraper

Booster Cables

Booster or "jumper" cables are used to transfer power to a discharged battery. See "Jump Starting An Engine" at the end of this chapter and carefully follow each step in the procedure for hooking up and removing booster cables.

Battery Carrier

A proper battery carrier will not place any undue strain on the battery terminals or container. A carrier that lifts a battery by its posts may damage internal components of the battery and create leakage at the terminals. An excellent carrier is a clamp ("ice tong") type carrier with rubber pads that grip the sidewalls of the container just below the lip of the cover (see Figure 11-8.) It is used on the sidewalls rather than the end walls, since the sidewalls have additional strength from the inner cell partitions. Gripping the flexible end walls of plastic containers could cause electrolyte to spew from some of the cells.

SELECTING THE SIZE

Replacement batteries should equal or exceed the Original Equipment battery in ratings. Replacing the original battery with one that has a lower capacity may result in poor performance and shorter life. If the replacement battery has considerably less capacity than the Original Equipment battery, it may not crank the engine adequately at cold temperatures. Difficulty may also be experienced in cranking high compression engines when they are hot. This "hot start" condition can sometimes impose a cranking load on the battery equal to loads experienced at cold temperatures.

A premium battery with marginally higher capacity than the Original Equipment battery will provide a safety factor that will result in longer service.

If the electrical load of the vehicle has been increased by the addition of accessories, and "stop and go" driving occurs frequently, a larger alternator or generator may be required. A larger alternator or generator will provide increased output at low speed operation and will improve battery performance.

Figure 11-8: Battery Carrier

If available, consult a replacement guide to ensure that the replacement battery is dimensionally correct for the vehicle, and that it is compatible with the hold down. If a battery is taller than the Original Equipment battery, be sure that top terminals clear the hood by at least 3/4" (19mm). To insure a perfect fit for the replacement battery, it should be the same BCI Group Size as the Original Equipment battery.

Before attempting to service a battery, read and understand the safety precautions outlined in Chapter 2. Always wear a face shield or safety goggles when working on or near batteries.

PREPARATION OF DAMP-DRY BATTERIES

Batteries should be reasonably charged before installation.

See Chapter 6 for battery installation.

PREPARATION OF DRY CHARGED BATTERIES (ACTIVATION)

"Dry charged" batteries must be activated as described below before they can be used.

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ACTIVATION - DRY CHARGED BATTERIESNOTE: AGM dry-charged batteries may require different activation procedures. Consult the manufacturer’s directions for appropriate procedures.

Fill each cell of the battery to the top of the separators with the correct battery-grade electrolyte as specified in the manufacturer's instructions. Using higher or lower specific gravity electrolyte than that recommended can impair battery performance. Filling each cell to the top of the separators allows for expansion of the electrolyte as the battery is boost charged.

Dry charged batteries may be placed in service immediately after activation. However, to insure good performance, the following additional steps are recommended:

Check the specific gravity of all cells. Under good storage conditions, the specific gravity upon activating a dry-charged battery will drop approximately 0.010 points and the temperature will rise 7° to 10°F (4° to 5.6°C) within twenty minutes of activation. A battery under these conditions requires little boost charging. However, should the specific gravity drop 0.030 points or more, with a corresponding increase in temperature, the negative plates are oxidized and the battery should be FULLY RECHARGED before use. In addition, the battery should be recharged if one or more cells gas violently after the addition of electrolyte.

After electrolyte is added, check the open circuit terminal voltage of the battery. If a 12-volt battery reads less than 11 volts (less than 5 volts on a 6-volt battery), this is an indication of either a reversed cell, an "open" circuit, or a shorted cell, and the battery should be replaced after fully testing.

When a dry charged battery has been activated and not put into service, it must be maintained, handled, and kept charged like any other wet battery.

When charging is necessary, boost charge batteries using an automatic charger or a fast charger on a medium setting until the specific gravity of the electrolyte is 1.225 or higher and the electrolyte temperature is at least 60°F (15.5°C). If the electrolyte gasses violently while charging, reduce the charging rate until moderate bubbling action is achieved.

If the ambient temperature is 32°F (0°C) or less, it is imperative that the above instructions be followed.

After boost charge, check the level of electrolyte in all cells. If required, add additional electrolyte to bring all levels to nearly the bottom of the vent wells. DO NOT OVERFILL. If the battery requires top-off while in service, add water. DO NOT ADD ACID.

REMOVING OLD BATTERYCheck owner's manual for special instructions. Consider attaching a back up battery to the system to preserve computer memories and prevent voltage spikes. Use care when utilizing a battery backup as the positive battery cable will be "hot" when the backup is connected.

Before removing the old battery, carefully note the location of the positive battery terminal and mark the polarity on the

positive cable. By doing this, you will avoid installing the new battery reversed. Remove the "ground" cable connector first. This precaution will avoid damage to wiring, and/or the battery, by accidental "grounds" with tools.

Use the proper size box, or open-end wrench (preferably with an insulated handle), when removing battery cables.

Remove the battery from the vehicle using care to keep the battery as near vertical as possible. This will minimize the possibility of spilling electrolyte and damaging appearance items on the vehicle.

Inspect the battery tray for possible damage or corrosion. Be sure that the tray and hold down are mechanically sound and free of corrosion. Corroded parts may be cleaned with water (to which some household ammonia or baking soda has been added) and scrubbed with a stiff brush. Cleaned parts should be dried and painted.

CABLESExamine the cables to be sure they are the correct size. Battery cables must carry large starting currents with a minimum loss of voltage, since engine-cranking speed is dependent on the voltage available at the starting motor. Reference the SAE J541 standard for recommended voltage drops.

Examine the cables to insure that the insulation is intact and that the terminal connectors and bolts are not corroded. Replace all unserviceable parts. Also, consider replacing cables that have temporary terminal ends bolted on. Temporary or emergency terminals may also alter overall installed battery height causing a catastrophic short when such things as fender supports are installed or when the hood is closed.

As the acid corrodes terminals and cables, their resistance increases, and the voltage loss between the battery and the starter increases. This increase in resistance due to corrosion can also limit the charging current to the battery eventually causing the battery to become undercharged and the plates will become sulfated. Be sure all cable connections are clean and tight. Voltage drop tests should be performed as needed.

Do not paint battery terminals. Clean and tighten the "ground" connections at the starter solenoid. Tighten starter relay and starter connections too.

INSTALLATIONBe sure the battery is charged as described in this section under "Preparation of Charged and Wet Batteries", "Activation - Dry Charged Batteries".

When placed in the vehicle, the battery should rest level in the tray. Be sure there are no foreign objects lying in the tray that may cause damage to the bottom of the battery container.

The hold down should be tightened until it is snug. It should not be tightened to the point that it will distort or crack the battery cover or case. Use torque values specified in the vehicle owner's manual. If they are not available, the following torque values may be used:

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The "grounded" cable should be connected to the battery last. Check for proper battery polarity with respect to the vehicle specifications. "Ground" polarity is usually indicated. "Reversed" polarity may cause serious damage to the vehicle's electrical system. Note that the positive tapered post is larger than the negative post.

Top bar or top frame hold down:

30-50 in-lbs / 3.4 – 5.6 N-m

Bottom recess type hold down:

60-80 in-lbs / 6.8 – 9.0 N-m

Bottom ledge type hold down:

70-90 in-lbs / 7.9 – 10.2 N-m

Figure 11-9: Using a wrench to remove or replace cable clamps on battery with terminals on top

The following torque values should be used when attaching battery cables to the battery terminal posts:

TORQUE VALUES

Tapered terminal posts (SAE):

50-70 in-lbs / 5.6 – 7.9 N-m

Side terminals: 70-90 in-lbs / 7.9 – 10.2 N-m

Stud terminals (3/8”): 120-180 in-lbs / 13.6 – 20.3 N-m

Stud terminals (5/16”): 100-120 in-lbs / 11.3 – 13.6 N-m

The cable terminals should be cleaned before connecting them to the battery. After all connections have been made, apply a thin coating of high temperature grease or petroleum jelly on the posts and cable clamps to retard corrosion. Use care so that insulating material is not applied to the battery post or inside of the terminal.

Never hammer cable clamps onto battery posts. In doing so, the cover, undercover post connections or post to cover connections can be severely damaged.

Figure 11-10(left): Battery with side terminal connections. Use ratchet wrench to tighten to specified torque values

Figure 11-11(right): Side Terminal Ratchet Wrench

Do not over-torque the terminal bolts of side terminal batteries. In doing so, threads may be stripped and the battery rendered useless.

When attaching side terminal connections, it is recommended that a side-terminal ratchet wrench be used to prevent over-torquing the bolts. (See Figure 11-11)

Never use side terminal bolts that are longer than the Original Equipment bolts. Longer bolts will damage the side terminal inserts and result in a potential explosion hazard.

Any time a new battery is installed, a check of the electrical system is recommended. Check to see if the starter, alternator or generator and voltage regulator are operating within specifications.

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Chapter 12 SERVICING BATTERY IN THE VEHICLE

Before attempting to service a battery, read and understand the "Safety Precautions" listed in Chapter 2. Always wear a face shield or safety goggles when working on or near batteries.

SERVICE PROCEDURESA customer should be made aware that a battery is a perishable item that requires periodic maintenance. With a reasonable amount of care, the life of a battery can be significantly extended. Neglect and abuse will invariably result in shorter life.

A routine "under hood" check of the battery can be made during periodic fueling stops. Maintenance should be automatically performed whenever the vehicle is left for other periodic services such as oil changes, tune-ups or minor repairs. Customers appreciate a technician who reminds them of needed services.

Proceed with routine servicing of the battery as follows:

Place a cover on the fender of the vehicle before doing any work.

Make a visual inspection for damaged cables, loose connections, corrosion, cracked cases or covers, loose hold downs and deformed or loose terminal posts. If any connections are clean but loose, tighten them as described under "Battery Installation", Chapter 11. If anything appears to be unserviceable, recommend replacement.

If there is corrosion on the hold-down, if the tray or hold-down parts are rusty or if the battery is dirty, it is recommended that time be taken to clean the parts. A wire brush can be used to remove dirt, corrosion or rust from the parts. Remove dirt from the top of the battery with a cloth that has been dampened with ammonia or a baking soda/water solution. Then, wipe with a wet cloth. After rust is removed from a part, rinse the part with clear water, dry, and paint with an acid-resistant paint.

If corrosion is found on the terminal posts, remove the cable clamps from the battery (ground cable first). Use a terminal

cleaning brush to clean tapered posts and the mating surfaces of lead die-cast cable clamps. Other terminal and clamp designs can be cleaned with an acid neutralizing solution and a non-abrasive brush.

Present day batteries do not normally require water additions, but if the battery is one that requires service, the second item in routine servicing of non-maintenance-free batteries is to check the electrolyte level in all cells. If water is required, distilled or de-ionized water is preferred. However, the addition of any water suitable for drinking is preferred to none at all. Bring the liquid level to the level indicator in all cells. If the battery does not have a level indicator, bring the level to 1/2" (13mm) above the tops of the separators. Do not overfill any cell. If a cell is overfilled, the excess electrolyte may be forced from the cell by normal gassing of the battery.

Tests can also be quickly run with a variety of rapid testers that can determine if the battery’s power level is still within an acceptable range. See “Alternate Battery Testers” in Chapter 6. These types of tests can often catch a weak battery and prevent an emergency battery replacement or roadside starting assistance.

JUMP STARTING AN ENGINE (BOOSTER CABLE INSTRUCTIONS)

BEFORE PROCEEDING, READ SAFETY PRECAUTIONS IN CHAPTER 2.

DANGER- BATTERIES PRODUCE EXPLOSIVE GASES. These instructions are designed to minimize the explosion hazard. Keep sparks, flames and cigarettes away from batteries at all times.

Both batteries should be of the same voltage (6, 12, etc.).

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SAFE BOOSTER CABLE OPERATIONWhen jump-starting, always wear proper eye protection and never lean over the battery.

Inspect both batteries before connecting booster cables. Do not jump-start a damaged battery.

Be sure vent caps are tight and level.

Make certain that the vehicles are not touching and both ignition switches are turned to the "OFF" position.

Refer to the vehicle owner's manual for other specific information.

The following steps should be followed exactly (Refer to Figure 12-1).

1. Connect positive (+) booster cable to positive (+) terminal of discharged battery.

2. Connect other end of positive (+) cable to positive (+) terminal of assisting battery.

3. Connect negative (-) cable to negative (-) terminal of assisting battery.

4. MAKE FINAL CONNECTION OF NEGATIVE (-) CABLE TO ENGINE BLOCK OF STALLED VEHICLE, AWAY FROM BATTERY AND FUEL SYSTEM.

5. Start vehicle and remove cables in REVERSE order of connections.

Figure 12-1: Hook-Up for Negative Ground Vehicles

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Chapter 13 CHARGING METHODS

CAUTION Lead acid batteries emit explosive gases while being charged. Review and follow all the safety precautions in Chapter 2 when handling and charging a battery.

Also, observe the following charging guidelines:

• Make sure the battery terminals are clean and free from corrosion.

• Do not attempt to charge a dried out battery. If needed, add distilled (or drinking) water to above the battery plates. Do not overfill.

• Refer to any written instructions provided by the battery and charger manufacturers.

• Identify the positive and negative terminals of the battery and attach the correct charger leads.

• If charging a battery connected to a vehicle, be sure that the vehicle’s electrical system has protection against over voltage or be sure that the charger will not have high charging voltages, that may damage the vehicle’s electrical system.

Lead Acid Battery ChargingA lead acid battery can be recharged after use or storage. The purpose of the recharge is to convert the discharged material (lead sulfate) in the battery plates back to lead dioxide (positive) and metallic sponge lead (negative). During the charging process, the electrolyte (sulfuric acid) specific gravity rises as the sulfate ions return to solution.

A battery's electric storage capacity is determined by its design, age, temperature, discharge rate and an array of other factors. A battery's capacity is maximized at full charge when all the plate material has been converted to lead dioxide and metallic sponge lead. As a charging battery nears full charge, its terminal voltage rises and/or the charging current falls – depending on the type of charger used. After the battery has reached a full state of charge, any additional charging will generate heat and some water is consumed by electrolysis causing hydrogen and oxygen gasses to be released from the battery. The excess heat is damaging to the plates (grids and pastes) and separators, whereas the loss of water lowers the electrolyte level and increases the specific gravity of the electrolyte. All of these factors can contribute to shorter battery life.

Battery chargers vary considerably as to the types and size range of batteries they may recharge and their mode of operation. Read the instructions carefully to determine if the charger is suitable, the proper settings to use and how long to charge.

Most starting batteries including VRLA types should be recharged with a constant-voltage type charger. Limiting the voltage to an appropriate constant level causes the charging

current (rate) to be automatically limited and continuously adjusted to less than the rate that will lead to excess gassing and water loss.

If only a constant current charger is available, a battery should be recharged at a slow charge rate, and the voltage should be monitored periodically as the end of charge is approached. This charging method should be avoided for batteries that cannot have water added for this consumes their water. For sealed batteries, flooded or VRLA, refer to Chapter 6 for further information.

If time is available, the lower charging rates in amperes are recommended. The lower rates must be used if the battery is suspected of having a problem (sulfated or possible internal defects) or if the battery temperature is below 15°F (-9°C).

A method of estimating the amount of recharge a battery requires is as follows:

1. Estimate the state-of-charge of the battery with a hydrometer or voltmeter. Subtract the state of charge from 100 to get percent discharged.

2. Divide the reserve capacity rating (minutes available at 25 amperes) by 2. This gives the approximate charge in ampere-hours needed to recharge the battery when completely discharged. Example: if the reserve capacity rating is 120 minutes, this value would be 60 ampere-hours.

3. Multiply the percent discharged in Step 1 by the charge needed for a full recharge when completely discharged from Step 2. This is the approximate amount of recharge the battery needs. Example: If the battery was found to be 75% discharged in Step 1, and the reserve capacity rating is 120 minutes, then 75% times (120/2) ampere-hours = 45 ampere-hours.

4. To determine the time required for recharging a battery, the calculated ampere-hours is divided by the charger current. Example: If a 4 ampere charger is used for the example in Step 3, the 45 ampere-hours divided by 4 amperes = 11.25 hours.

A good method to insure that a battery is fully charged when using a constant current charger is to measure the voltage of a battery once per hour. The battery is assumed to be fully charged when the voltage is nearly constant or falls over a one-hour period. Periodically monitor the battery temperature and condition. If the temperature exceeds about 125°F (51.6°C), or if excessive gassing or spewing of electrolyte occurs, the charging rate must be reduced or temporarily halted. This is done to avoid damaging the battery.

Before placing a battery on charge, clean the terminals if necessary. If needed, add enough water to cover the plates. Fill to the proper level near the end of charge. If the battery is extremely cold, allow it to come to room temperature before adding water because the level will rise as it warms. An

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extremely cold battery may not accept a normal charge until the temperature rises.

BATTERY HOOKUPSBatteries may be connected to the charging source in series, parallel or preferably individually, depending upon the type of charger used. For boost charging multiple batteries, parallel or series charging methods are sometimes used. More than one battery (all must be of the same voltage) can be charged on high-rate fast chargers. When this is done, connect the batteries in parallel, i.e., connect the positive (+) terminal of one battery to the positive terminal of the next battery and negative (-) terminal of one battery to the negative terminal of the next battery, etc. (See Figure 13-1.) NOTE: charging multiple batteries simultaneously is not recommended for battery testing applications, whether in parallel or series.

The number of batteries that may be connected in parallel depends on the current capacity of the charger. The output of the charger will divide equally among the number of batteries in parallel if they are identical (same rating, same state-of-charge, etc.) and there are no high resistance connections. For example, if five batteries are being charged in parallel, and the charger output is 20 amperes, each battery will normally receive approximately 1/5 of the total output, or 4 amperes.

Figure 13-1: Parallel Connection

A series connection is one in which the positive (+) terminal of one battery is connected to the negative (-) terminal of the next battery, etc. (See Figure 13-2.) Each battery in the series connection receives the full current output of the charger.

The number of batteries that may be connected in series is dependent upon the voltage rating of the charging source. Batteries with different capacities can be charged in series, but the proper charge rate and charging time for the lowest capacity battery must be used.

WARNING: Chargers designed to charge several batteries in series may be capable of producing dangerous voltages. Dangerous voltages are present in long strings of batteries even when no charger is connected.

Figure 13-2: Series Connection

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COMMON BATTERY CHARGERS, THEIR CONTROLS AND CHARACTERISTICS

1. Constant Voltage ChargerThis type of charger charges a battery at a fixed charging voltage, usually above 13.8 volts and usually well below 18.0 volts for 12-volt batteries. The voltage setting should be adjustable in order to charge as many different types of batteries as desired. By design, all chargers have some current or power limit. Initially, a discharged battery may accept the maximum current or power that the charger can provide. The voltage will rise as the charge continues until the constant voltage level is reached. As long as the charge acceptance is less than the limit, the charger will continuously adjust the charging current to maintain a constant voltage at the output. As the charging continues, the battery's demand for charging current decreases. A full charge can be recognized when the charging current has fallen to a low level and changes very little over a one-hour period. In practice, a combination of current acceptance and time is typically used in deciding when to stop charging. This type of charging is similar to what the battery sees in an actual vehicle that has its alternator output controlled by a voltage regulator.

2. Constant Current ChargerThis type of charger charges a battery at a preset or adjusted rate of constant current. While being charged by a constant current charger, the battery voltage will rise as the state of charge increases. The voltage rise of each battery under charge has a natural limit, usually lower for the antimonial alloy batteries and higher for calcium alloy (maintenance-free) batteries. When the battery is fully charged, unlike the constant voltage chargers, the charging current will not decrease but will remain constant. Any charge after the battery is fully charged will result in increased battery temperature and gassing.

3. Taper Current ChargersTaper charger output voltage varies with the output current. The lower the current is, the higher the voltage is. This curve is typically linear. It is not constant power. Many models have multiple settings. The voltage across a charging battery depends on its charge level and the charging current. The higher the voltage across the battery, the higher the charging current will be. Where these two curves intersect determines the current and voltage at each instant. As the battery’s charge level increases, the charging current will decline and the voltage will increase. When both the current and voltage change very little over a 1-hour period, a full charge has been achieved. Chargers of this type are especially effective for flooded deep-cycle batteries and are good for the occasional recharge of flooded automotive batteries. This method ensures that some gassing will occur near the end of charge to thoroughly mix the electrolyte, while ensuring that this occurs only at a low current. With parameters

appropriate to the battery being charged, this delivers sufficient overcharge without excessive overcharge.

4. Automatic ChargersAutomatic chargers have included within them circuits that monitor and/or control battery voltage and/or current. Since the ideal charging voltage depends on battery temperature, battery temperature may also be monitored. Many automatic chargers have a delayed start feature and can sense polarity to prevent sparking on hookup and charging in reverse. Some chargers have settings for different sizes and types of battery. When appropriate settings are used, automatic chargers turn off automatically when the battery is fully charged. Automatic chargers are generally recommended because they can provide a safer, full charge with limited operator skill or knowledge.

An automatic charger may use a series of charge steps set to different constant current or constant voltage levels. The final step is often a float charge of indefinite length.

5. High Rate or Boost Fast ChargersHigh rate fast chargers are able to provide high charging currents regardless if the current is used to convert the battery's active material or not. A charger that can put out over 40 amperes continuously is considered a high-rate, fast charger. The fast charging rate is usually greater than the active-material conversion rate. With high rate chargers, battery overheating and gassing is likely if the charger is left unattended for too long. It is for this reason that most fast chargers come with a timer for cut off.

The reason for high-rate, fast chargers, sometimes referred to as boost chargers, is to quickly get enough charge into a discharged good battery, in order to start a vehicle. Some chargers may be left running while the engine is cranked to provide assistance during cranking. Excessive charge rates are not recommended for unattended or long-term recharge of a battery. However, these chargers may have other settings that can be used effectively for a proper recharge.

6. Trickle Chargers and Float ChargersTrickle battery chargers are small constant current chargers. Normally, their charging rate is much less than one ampere per battery, and sometimes less than 0.03 amperes per battery. A trickle charger is not designed to charge a completely discharged automotive battery. Its sole purpose is to maintain a battery at its full state of charge, over a long period, by replacing its self-discharged capacity. However, without voltage-regulation, a small current over a long period may increase grid corrosion.

Float chargers maintain the battery at a full charge state by use of a constant voltage charge. The voltage is slightly higher than open-circuit, but lower than a typical charge voltage. This causes a very small current to flow. At the ideal voltage, the grid corrosion rate is at a minimum.

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Chapter 14 CAUSES OF BATTERY FAILURE

Batteries have a limited life that is determined by both design and application. Some major factors affecting life of a given battery are the temperature profile and the usage profile. The temperature profile varies with climate, vehicle design, and vehicle usage pattern. Higher temperatures can greatly shorten battery life. Usage profile refers to the number of discharges and the depth of each discharge. Most starting batteries are discharged very little between starts. Supplying loads for long periods with the vehicle off will shorten life. Because of these differences, “normal” battery life is expected to vary greatly. By selecting a battery with design features appropriate to the climate and expected usage, service life can be maximized. However, if the customer has experienced “premature” failure, it is important to determine the cause so that a recurrence of the problem can be prevented.

Batteries contain materials that may be hazardous if opened. Examples of internal examinations are given for educational purposes only. The internal examination of a battery should only be performed by experienced personnel in facilities equipped to handle and dispose of hazardous materials.

BATTERY APPLICATION AND INSTALLATION1. Is the battery being used in the application for which it was

designed? For example, a standard automotive battery used in a recreational vehicle designed for a deep cycle battery is an obvious misapplication.

2. Is the battery sized properly for the application? Are both the Cranking Performance and Reserve Capacity rating at least equal to the vehicle's Original Equipment requirements?

3. Does the vehicle have excessive electrical accessories, particularly those that have been added to the vehicle? Examples of added accessories include winches, lights, amplifiers, etc. If additional accessories have been added, the charging system may need to be upgraded. A higher capacity battery will help, but ultimately, the charging system output must exceed the charge consumed or even the largest battery will become discharged.

4. Is the battery properly fitted into the vehicle? Have hold-downs, heat shields, or battery trays been modified or removed? Does the battery's BCI Group Size match the vehicle's Original Equipment requirements or equivalent?

5. Have the battery cables been cleaned and have they been properly adjusted to fit the battery terminals? Have the terminals been converted from side to top terminals or vice versa? Has the battery been relocated to a remote location?

SERVICE HISTORY OF THE BATTERYAsk the owner to give you any information concerning not only the history of any problems with the battery, but also with the vehicle.

1. Has the vehicle's electrical system been repaired or altered? Have there been any problems with the lighting? The charging system has a significant effect on battery life.

2. Has the vehicle been driven regularly or has it been parked for an extended period? Batteries will discharge with time, especially in newer vehicles that draw on the battery even when it is not running.

3. Has the vehicle been brought in from or driven in another part of the country for an extended period? High temperatures will greatly reduce battery life.

4. Has the vehicle been difficult to start for any reason? Starting problems may have placed excessive loads on the battery or may indicate an undersized battery.

5. Did the battery tray need to be washed free of corrosion or electrolyte? This may indicate damage to the battery container, overcharging or a shorted cell.

VISUAL INSPECTIONAn external inspection of the battery may reveal signs of the cause of failure.

1. Do the terminals show signs of having been hammered, twisted, or driven down into the cover? Do side terminals show signs of over-torquing? Over-torquing can cause internal damage that can't be seen.

2. Does the container or cover show signs of stress, damage, or high temperature? Does the container or cover have worn areas indicating vibration damage?

3. Are the ends of the battery pushed out? This can indicate plate growth.

4. Are the vent caps installed properly? Do they appear to be the original vent caps? Improperly installed or missing vents can be the cause of an explosion, leakage, or contamination. Unless the battery manufacturer recommends it, vent caps should not be removed.

5. If the vents caps are removable, check the electrolyte levels in all cells. Are they below the tops of the plates in any or all cells? Low electrolyte levels in all but one or two cells may indicate an internal short. Low levels in all cells may indicate overcharging. If only one cell is low, there is most likely damage to the bottom of the container.

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6. Draw some of the electrolyte into a hydrometer. Is it cloudy, discolored, or contaminated with foreign material? Cloudy or discolored electrolyte may indicate material shedding due to overcharge, deep discharging, or vibration. Electrolyte contamination may be from oil or other foreign substances being added to the battery.

BATTERY AGE AND DATE CODINGThe battery's age can be an important factor in determining the cause of failure. The length of time in service determines whether the battery failed prematurely or simply wore out. The important date is when the battery was sold. This date determines the time the battery has been in service. The date of purchase is sometimes indicated on a label that has the month and year printed so that they can be removed. If this information is not available, check with the vehicle owner to see if the original sales receipt is available.

There are usually two other dates placed on the battery by the manufacturer. Battery manufacturers date their product usually by permanently stamping a date code into the cover or container. This date code can be used to determine the actual age of the battery. These codes usually have information unique to the manufacturer, but within this code is the manufacturing date. Often the month is coded chronologically A through L or M (some companies exclude I). The last digit of the year is usually indicated by the numerals 0 - 9.

Most manufacturers also place a small label on the battery with the month and year noted when it is shipped to their customers. While not an accurate means of determining the time in service, it usually will be no more than six months earlier. The coding is similar to the manufacturing code. If you need this information and cannot determine the coding, consult with the individual manufacturer concerning specific date codes.

OVERCHARGING AND UNDERCHARGINGThe battery is just one part of the vehicle's electrical system. The charging system or small continuous discharges can have a great effect upon the life of the battery. A bulb under the hood or in the trunk that stays on when the vehicle is not running can discharge the battery. With normal driving, this is usually not enough to cause the vehicle not to start, but it will have an effect on life. The repeated discharging and recharging of the battery will shorten life.

Most of today's vehicles have solid-state voltage regulators that are typically integrated with the generator. The regulators eliminate the problem of adjusting the voltage setting. These settings are made by the manufacturer for the typical service requirements of its vehicles. However, if the examination of the battery indicates an overcharge or undercharge problem, the voltage setting and the output of the generator need to be verified. A generator (alternator) or voltage regulator failure will typically result in corresponding battery failure. Since the electrical output should be checked over a wide operating range, it may be necessary to use a computerized testing unit that can simulate all ranges of operation. There are also battery testers that have charging system tests included in their functions.

FAILURE MODESThe internal condition of a battery is usually the best indicator as to the cause of failure. The following information describing the internal examination is for informational value to the service technician in the field. Service technicians in garages should not disassemble a battery. As noted earlier, this should only be performed by trained personnel with the proper facilities to assure that no hazardous materials are released. If you have a need for a detailed analysis of the cause of failure, contact your distributor. In some cases, the manufacturer will arrange to take the battery back to its facility for analysis.

The following paragraph shows a typical procedure for analysis.

The battery is first examined externally. Check for obvious physical damage.

• Check the terminals. Are they pushed in, badly scarred, arced, or show other physical damage? These will give you clues to any possible connection problems and give an indication as to where to examine internally.

• Check the container, cover and vent caps. Are there any cracks that could be due to an impact blow or freezing? Are all vent caps in place? Is the container distorted? These could be indications of abuse, over-tightened hold-downs, or high temperatures. Very small leaks can be detected by washing the battery, drying it, and setting it on a clean, dry piece of paper overnight. If there is a leak in the bottom of the container, it will produce a wet spot. This could indicate that a bolt or some other hard object was in the battery tray.

• Check for material on the battery. Is there grease or dirt on the cover? Is there excessive dirt or road material on the cover? Are there stains down the sides of the battery? Foreign material on the cover can cause self-discharge and affect the charging system. Stains may be from electrolyte running down the battery. This could be from excessive charging or leakage between the cover and container seal.

• Check the open circuit voltage of the battery. If accessible, remove the vent caps. Using a hydrometer, take the specific gravity of each cell. When doing this, note the level of each cell and the appearance of the electrolyte. If one or two cells vary more than 50 points, these probably are the cause of failure. Also, note any large variation in levels. If the electrolyte appears "muddy", then active material has shed from the plates. An unusual odor may indicate an impurity has caused the battery to fail.

Attempt to recharge the battery. Add water to the top of the separators if necessary. Charge with an automatic charger meant for the battery type or at approximately one percent of the Cold Cranking rating. When the battery is fully charged, record the open circuit voltage and specific gravity of each cell. Allow the battery to stand for one or two days. Measure the voltage and specific gravity again. An excessive drop in voltage indicates that a short exists. A drop in specific gravity between cells of 35 points or more is an indication of a short in one or more of the cells.

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Positive Plate

Failure modes of the positive plate can be related to either or both the grid or the active material. Service life will depend upon the specific grid alloys and dimensions, plate chemistries and processes used in the manufacture of the grids and plates. These typical failure modes may be seen as the battery reaches the end of its operational life. If the following failure modes are found early in life, the cause may be due to manufacturing techniques or external causes.

Figure 14-1: Positive Plate disintegration due to collapse of grid mesh, corroded by overcharging

Figure 14-2: Sulfated Positive Plate

If the positive plate breaks apart under slight pressure, the grid wires have corroded (see Figure 14-1). As the battery ages, these wires are oxidized thus reducing the cross-section of the wires. This process can be accelerated by overcharging. Continued

overcharging, after the battery is fully charged, begins to "form" the wires. In the long term, overcharging is difficult to separate from normal aging unless there is a pronounced water loss.

Another form of corrosion is grid growth. With some alloys, the grid will grow or expand to the side and toward the top as the battery ages. As with the plate disintegration noted above, this is a normal aging process. Usually the plate will grow until it shorts against the underside of the plate straps thus causing failure. This too can be accelerated by overcharging and/or high temperatures.

If the plate material is hard and light brown in color, it is very discharged. Sulfation (see Figure 14-2) occurs when the battery stands in a partially charged state for long periods or is constantly undercharged. Depending upon the length of time the battery has been in this condition, the sulfation may be irreversible. Irreversible sulfation covers the positive plate with large crystals or crusts of lead sulfate. This typically occurs from abuse such as: (1) allowing a battery to stand in a discharged condition for a considerable time; (2) operating the battery at excessive temperatures; (3) persistent undercharging; or (4) adding acid (instead of pure water) to a battery that requires periodic water additions.

If the plates are buckled (see Figure 14-3), the battery may have been overcharged while sulfated or stored in a deeply discharged state. A buckled plate typically occurs if there is a greater paste thickness on one side of the plate than the other—for example with a plate produced on a belt paster. Grid frames can also be cracked if the plates are buckled.

Figure 14-3: Buckled Positive Plate

Uniform shedding over the entire surface of the positive plates is normal for a battery after long service. If the material has shed from the plates in small chunks, it could be due to vibration, high charging rates on sulfated plates, or the battery freezing (see Figure 14-4). When caused by vibration, there will be worn areas within the element. Also, check the external container for areas that are worn from rubbing on the tray or hold-downs. Shedding due to recharging sulfated plates will also have the characteristics noted in sulfation above. Excessive cycling of a starting battery promotes shedding. The material shed is very fine and forms dark brown mud. The shed material may be lifted by gassing and dropped on top of the element where it can build up to form “mossing” shorts when it reaches plates or straps of the opposite polarity

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Figure 14-4: Positive plate exhibiting material shedding in small chunks

Negative Plate

The active material of the negative plate contains sponge lead. Sponge lead is usually slate gray in color. A good, fully charged negative plate will have a metallic sheen when a spatula is rubbed across it. If a metallic sheen is not created, the negative material is sulfated.

A partially charged negative plate will have a dull gray appearance. If testing shows that the battery is fully charged and the plates have a dull, sandy appearance, the plates are inactive. These conditions could indicate a short circuit or operation at high temperatures and high specific gravity. If this condition has been present for some time, the negative plate material may be soft. Earlier testing will have indicated short circuits or high specific gravity.

If the negative plate is hard, with a dull almost white discoloration, this is a sign of sulfation. The accumulation of lead sulfate is the result of undercharging or being left in a partially charged state for a long period. If the sulfation is on the upper portion of the plate with a distinct line, the plates have been exposed to the air for a long period. This is due to low electrolyte levels and is present on the positive plate as well (see Figure 14-5). More typically, batteries will show sulfation at the bottom of the plate because stratification of the electrolyte produces high concentration gradients at the bottom of the battery that limit charging and induce self-discharge. This may in turn result in preferential paste shedding on the top half of the positive plates, which become overworked in this situation.

Negative plate sulfation is a typical failure mode in high-temperature partial state of charge applications using valve-regulated batteries, valve-regulated batteries float charged for many years, and valve-regulated batteries that have had the valves opened or that have small air leaks. Hydrogen and oxygen in a valve-regulated battery are initially in balance. Additional oxygen from outside or a loss of hydrogen not offset by an equivalent loss of oxygen via positive grid corrosion leads to an oxygen surplus that makes completely recharging the negative plate impossible. As the oxygen surplus enlarges over time, the state of the negative plate deteriorates progressively. The perpetually discharged material will tend to be found on the plate surface.

Figure 14-5: Sulfated Negative Plate

High temperatures, with exposure to high concentration electrolyte, and cycling and/or overcharge can lead to other problems with the negative active material. When the negative active material becomes soft, mushy, shrunken, blistered, checked or granulated, the spongy high surface area pore structure of the active material is compromised and performance is degraded.

Separators

When inspecting the element, look for misaligned or short separators. Envelope separators, by their design, protect from misalignment. A short envelope can occur on one side when the fold is not even. Holes in a separator envelope can often be found by filling the envelope with water and noting where the water runs out. Hold the separator up to a light. Open envelopes before checking. You can then inspect for holes, tears, or other visible damage through the separator. If there is a large amount of material adhering to the separator, you may have to wash the separator to reveal small holes or dendrites.

Holes, splits, pinholes, and other similar defects are readily identified when the separators are held to a light. Holes may be caused by a number of conditions, including: puncturing through the web by a loose fragment of grid wire, lumps of paste that apply pressure on the separator and wear a hole through it, or burned through areas caused by bent or buckled plates.

Dendrite shorts, also called hydration shorts, occur most commonly in acid-limited batteries. During manufacture or service, if the electrolyte concentration falls excessively low, lead sulfate becomes quite a bit more soluble than normal. The dissolved lead sulfate diffuses throughout the cell, and when the cell is subsequently recharged and the electrolyte concentration rises, this excess lead sulfate must be deposited somewhere. Some of this material may be deposited in the pores of the

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separator where it can create an electrical path (small short) between the electrodes.

Shorting due to pinholes or dendrites can be observed by deposits of gray negative material on the positive plates. The location of these deposits will match the location of the separator where the short occurred.

SUMMARYWhen a battery failure is premature, the reason for failure is usually the result of a single cause. Careful inspection will lead to that case even when secondary failures have occurred due to

the primary cause. If the cause of failure is not evident in the first element inspected, inspect the other elements until the cause of failure is determined. It is best practice to isolate the magnitude and area of failure with electrical tests prior to disassembly.

If the battery has been in service for a prolonged period, it will usually fail due to multiple causes. This is the natural failure mechanism of a battery. All batteries have a limited life and will eventually fail. Actual service life will be a function of the design combined with factors from the application. When multiple causes of failure are noted in older batteries, this indicates a good balance between design, materials, and application.

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Chapter 15 AUTOMOTIVE CHARGING SYSTEMS

SAE J1930 TERMINOLOGY

The standardized names for the various terms and components used in automobiles have been published by the Society of Automotive Engineers' (SAE) list of terms entitled J1930.

INTRODUCTION

The battery, generator and regulator make up the charging system of the vehicle. Each performs a unique function but all have one thing in common: If a problem exists in any of these three units, it can manifest itself as a battery failure or a failure to crank the vehicle due to a discharged battery.

The generator, commonly referred to as an alternator, is an electromechanical device responsible for converting mechanical energy from the engine into electrical energy for the ignition, lights, blower, radio and other electrical accessories when the

engine is running. Under certain speed and electrical load conditions, the battery and generator both supply the current to the electrical loads. Then, as the vehicle speed increases or the electrical loads decrease, the generator supplies all the current necessary to operate the accessories and to charge the battery.

Generators operate on the principle of electromagnetic induction. That is, a magnetic field moving past a stationary conductor will cause a voltage to be created in the stationary conductor. For conventional automotive generator design, the stationary conductor is called the stator and the moving magnetic field is provided by a coil located on the rotor. Current will flow when an external load is connected across the stator output leads.

The output from the stator must be rectified or converted from AC (alternating current) to DC (direct current) in order to be used to charge the battery. The conversion is performed by diodes located in the rectifier assembly of the generator.

D.C. GENERATOR (ALTERNATOR)

Figure 15-1: GENERATOR DESIGN FEATURES - Diode Rectified Generator

VOLTAGE REGULATOR

A voltage regulator is included in the charging circuit to limit the generator output voltage to a suitable value. Without the regulator, the generator output voltage would increase proportionally with engine speed and become excessively high for all electrical components including the battery.

The regulator is a small module typically mounted at the back of the alternator. It is made up of two parts: the electronic module and the brush holder. The electronic module senses system voltage and turns the field coil on or off by permitting current to flow through the brushes, to the slip rings and ultimately on to the field coil. The brushes are spring loaded in a holder so that

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they can maintain electrical continuity under all operating conditions and as they wear.

A voltage regulator controls the generator's output voltage by turning the rotor field coil on or off in response to system demands. The regulator increases generator current output to recharge the battery when battery voltage is low and electrical accessory load is high. This means that the regulator will permit accessory operation under a heavy electrical load with little drain on the battery. In this case, most of the current will come directly from the generator. Generator current output is reduced when the battery is fully charged and the accessory load is low.

Most voltage regulators are temperature compensated. The nominal system voltage is set to approximately 14.4V @ 77°F (25°C) for a 12V charging system. The system voltage is then decreased below the nominal as the battery temperature increases above 77°F (25°C). Conversely, the system voltage is increased above nominal if the battery temperature is below 77°F (25°C). Ideally, variation from the nominal voltage would be based on the changes in the battery temperature. Since it is not practical to measure the internal battery temperature directly, it is estimated from other temperatures that are correlated to battery temperature. The purpose of temperature compensation is to account for the charge acceptance and overcharge characteristics of the battery that vary directly with temperature.

The service life and performance of the battery can be influenced by the charging system specification established by the manufacturer. Charging voltages that are set too high for a particular battery technology may result in overcharge and reduced life. Settings, which are too low, can result in undercharging, reduced performance and eventually a discharged battery.

CHARGING VOLTAGE

The voltage measured across the battery terminals when a battery is being charged by the generator is called the charging voltage. The charging voltage is the sum of the battery open-circuit voltage, the energy added to force charging to occur, and the energy lost due to the internal resistance of the battery.

The battery charging voltage and the generator output voltage specified by the logic of the regulator are practically the same with some exceptions:

1. At a given rotational speed and temperature, there is a limit to the current that can be delivered at the desired voltage. If the total loads, including the charging current to the battery exceed this limit, the target voltage level will not be achieved. This does not necessarily result in the battery discharging, just charging slower. Discharge will occur only if the loads, not counting the battery, exceed the maximum charging system output under the prevailing conditions.

2. The typical voltage regulator measures the voltage at the generator. The total circuit resistance between the generator and battery will introduce a voltage drop between the generator and the battery. This voltage drop is proportional to the current in the circuit; so, measuring voltage drop when the current is low will not show its true value.

REGULATION

When charged with a constant voltage, a battery’s charge rate decreases as its state of charge increases. This is mainly because the charge rate is driven by the potential or voltage differences between the charger and the sum of the battery open-circuit voltage, the energy already added to the battery by charging, and the energy lost due to the internal resistance of the battery. The charge rate decreases as this potential difference decreases. Therefore, when charged at a proper constant voltage, the battery to a great extent automatically regulates its charging current to a reasonable level.

Figure 15-2 shows the relationship between charging voltage, charging current and state of charge of a typical starting battery around room temperature. The graph is divided into two areas - a white area and a gray area. The dividing line between white and gray is at 14.4 volts; this represents a typical voltage regulator setting or "limit" for a 12-volt system. The operating point of 14.4V occurs unless the total current demanded is too high for the generator at the prevailing conditions. This chart demonstrates that the state of charge cannot be determined by the charging voltage alone. One must also consider the charging current.

Figure 15-2: Battery Terminal Voltage Graph

Figure 15-3 shows how some of the Figure 15-2 curves are affected by temperature. Note that at any particular voltage and charge state, the warmer the battery is, the higher the charge rate is. The effects of temperature on charge rate can be partially mitigated by using a higher charge voltage at lower temperature.

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Figure 15-3: Battery Terminal Voltage Graph (NOTE: This table shows typical relative values, and is for illustrative purposes only.)

The effect of temperature on regulation is the reason that most regulators are temperature compensated. Transistors and diodes, components of voltage regulators and other modules, have parameters that naturally change with temperature. By choice of components and design of the circuit, the variation in output voltage with changes in temperature can be made to mimic a standard battery temperature compensation curve. As the regulator or other sensing module temperature decreases, the charging voltage is increased. Conversely, as the temperature increases, the voltage is reduced

Since the battery is essentially a chemical "device", its charging properties are often altered by chemical changes in the battery itself. Sulfation is the change in the lead sulfate that normally occurs with discharge that limits its ability to recharge. The effect is particularly focused on the negative electrode. Sulfation may be a major problem if it is allowed to become excessive. Since sulfation is likely to occur whenever batteries are neglected for long periods, it can occur in new batteries in stock as well as in used ones. A battery that is severely sulfated will not accept an adequate charge rate from the generator and will eventually become discharged. This is why systematic care of batteries in stock is a necessity. If they are not kept in a satisfactory state of charge, they will become sulfated and lose their ability to accept a charge at normal vehicle charging voltages.

It is possible for a vehicle to develop an undercharged battery if it is constantly driven at slow speeds, and idled for long periods, as in very heavy traffic and combined with high electrical load conditions. Applications in which persistent undercharging most often occur are infrequently used private cars, delivery trucks, and some buses. Key-off vehicle parasitic loads, such as, clock, electronic control systems, theft deterrents, etc., while small, may also lead to a discharged battery if the vehicle is parked for an extended period. Vehicle manufacturers may recommend

disconnecting the negative battery lead if the car is to be stored for a month or more.

Some vehicle electrical systems now have battery run down protection features that reduce inadvertent battery discharges. They may, for example, automatically disconnect non-critical parasitic loads during long vehicle storage or turn off interior lights left on inadvertently by the driver.

PRECAUTIONS TO BE OBSERVED WHEN SERVICING CHARGING SYSTEMS

1. Reversed battery connections may damage the vehicle's rectifier, wiring or other components of the charging system or electrical accessories. If the battery has to be removed, note which terminal post is connected to "ground" and identify it in some fashion.

2. When jump starting a vehicle, the booster cables must be connected properly in order to prevent damage to the vehicle's charging system or any other electrical components. See "Jump Starting an Engine" in Chapter 12.

3. Care should be taken when connecting a fast charger that does not include a polarity or generator protecting circuit. Refer to the charger manufacturer’s instructions for proper connection procedures.

4. The field circuit must not be grounded at any point. Grounding of the field may damage the regulator. Extra care must be taken when working near this electrical system. Always follow the manufacturer's instructions for proper diagnosis and testing procedures.

5. Grounding of the generator output terminal will damage the generator and/or circuit components. Unless the regulator is equipped with a circuit breaker, this terminal is "hot" even when the system is not in operation. Never ground the output connection of the generator.

6. Generators should not be operated on open circuit with the field winding energized. Doing so will result in high voltages which may cause rectifier damage. Make sure all connections are secure.

7. Do not connect or disconnect a battery cable without first turning "off" the engine. A high voltage spike is produced when the cable is disconnected from a vehicle in which the engine is running; a high voltage spike may damage generator diodes or integral voltage regulators.

Note: A similar voltage spike occurs when the cable is reconnected.

8. Do not jump start 12-volt vehicles with a 24-volt power supply (two 12-volt batteries in series or a 24-volt motor generator). The vehicle's electrical system may be damaged.

9. Some vehicles produced in recent years may exhibit unusual driving characteristics for several miles after the battery has been discharged and/or reconnected; the reason for this is the loss of some learned computer memory. See the vehicle manufacturer's procedures for methods to hasten the reestablishment of this memory.

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Chapter 16 VRLA BATTERIES

INTRODUCTION

HISTORYThe first spill-proof, lead-acid batteries that did not require water additions were developed in the mid-1960's in Germany. These batteries were called "Gel Cells" because of their unique gelled electrolyte. The acid electrolyte had the consistency of "Petroleum Jelly" and was made by mixing the sulfuric acid with silica powder. These batteries also featured a pressure release valve and nearly eliminated water loss through a process called oxygen recombination. Because they were spill-proof and did not require watering, gelled-electrolyte batteries quickly found their niche in applications such as emergency lighting.

In the late 1970's, another type of spill-proof, no water addition lead-acid battery was developed. Instead of using gelled electrolyte, this type of battery used a unique, very absorbent separator to hold the electrolyte like a sponge. These batteries utilized a non-woven separator made from spun-glass microfibers that absorbed and held the electrolyte. These batteries were appropriately named Absorbent Glass Mat Batteries, or just AGM for short. Like their gel battery counterparts, AGM batteries also operated on the principle of oxygen recombination. They have gained popularity in other applications such as telephone and computer back-up and automotive starting.

In the early days of gelled and AGM batteries, the term Valve Regulated Lead-Acid (VRLA) did not yet exist and these battery types were referred to as Sealed Lead-Acid Batteries (more commonly called SLA batteries). This term was somewhat misleading to users because these batteries were not TOTALLY sealed in the sense of being hermetically sealed. These batteries do operate under a slight pressure and vacuum and can release very small amounts of gas during their operating lives. It is for this reason that the term SLA was confusing and caused more problems than solutions. In fact, some users took the SLA name verbatim and designed the batteries into airtight cabinets with other electrical equipment. The industry strove to eliminate the confusion associated with the term SLA and coined the name Valve Regulated Lead-Acid. To this day, the term VRLA is specifically intended to give the user a sense that the battery is operating in essentially a sealed manner and does not require water addition, but does periodically release gasses.

OXYGEN RECOMBINATIONThe process of oxygen recombination is used in VRLA batteries to eliminate water addition during the entire life of the battery. As mentioned above, gassing is not totally eliminated but is reduced to a minimal level. This is accomplished in the following manner:

First, a pressure relief valve is used on each cell or battery to ensure that the cells are airtight and operate under a slight positive internal pressure. Therefore, when the cells approach

full charge and gassing begins, the gasses are contained within the cell by the pressure relief valve in its closed position.

Second, the cells are designed to be acid starved, which means that the separators are only 90-95% saturated with electrolyte. In the VRLA battery, the positive and negative plates are not immersed in acid like in a conventional automotive SLI battery. Because of this, the plates are exposed to the gasses that are contained within the VRLA cell.

Finally, it all comes together when the VRLA cell is being recharged and the cell nears a full state of charge. As normal gassing begins within the cell, the closed pressure relief valve causes the cell pressure to increase. Most of the oxygen produced at the positive plates migrates through the unsaturated separator spacing and comes in contact with the negative plates where it reacts with the highly active sponge-lead to form lead oxide. This lead oxide instantly combines with the sulfuric acid in the electrolyte to produce lead sulfate and water. Therefore, this net reaction serves to convert oxygen back into water and thus the term "oxygen recombination" was coined. An added benefit of the oxygen recombination reaction is that the negative plates become partially discharged and do not reach a voltage at this time, which produces hydrogen. The net result of the recombination process is a battery that releases minimal gas and does not require water additions over its entire operating life. It is for this reason that VRLA cells are also referred to as recombinant cells.

It should also be pointed out that VRLA cells must remain airtight at all times. The pressure relief valve must never be removed or loosened. As mentioned above, air-tightness is required for the oxygen recombination process to occur efficiently. If air is permitted to enter the cell from the outside, the oxygen in the air will react with the negative plates and the cells will become imbalanced (self-discharged). It is for these reasons that good valve seals, cover seals and post seals are so extremely important.

VRLA batteries differ from flooded batteries in the way gassing occurs at full charge. The main differences relate to the oxygen recombination process. In a flooded battery, both the positive and negative plates are gassing freely near the end of charge and are producing stoichiometric amounts of hydrogen and oxygen, i.e. two parts hydrogen and one part oxygen. In a VRLA battery, only the positive plate is gassing freely to produce oxygen near the end of charge. The negative plate is not gassing freely because it is involved in the oxygen recombination process. Oxygen recombination lowers the negative plate voltage and therefore, the negative plate is only able to produce very slight amounts of hydrogen. The net result is that VRLA batteries require a lower charging voltage and therefore, must be charged using a charger specifically designed for this type of battery.

Because of the negative electrode’s affinity for oxygen, during stand and float charging, gas in the headspace of a VRLA battery is largely hydrogen reducing the potential for explosive gas combustion with an internal spark.

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CELL CONSTRUCTION

AGM vs. GELAs described previously, VRLA batteries may be either AGM construction or gelled acid construction. The Absorbent Glass Mat design involves the use of a non-woven microglass-mat separator that is soft, compressible and very absorbent. In a manner very similar to a disposable baby diaper, the separator absorbs and holds the electrolyte. The separator is 92-96% porous and actually absorbs 7-8 times its weight in acid. The AGM cell is designed so that the thickness of the plates and AGM separators fit into the cell case very tightly. In fact, most AGM cells are designed so that the AGM separators are ultimately compressed 20-30% when stuffed into the cell case. This gives the cell the needed plate-to-separator interfacial contact and makes this cell very vibration resistant. The highly porous nature of AGM separators leads to lower internal cell resistance and better high-rate performance than gelled electrolyte batteries, which use the typical plastic/polyethylene separator.

In the gelled electrolyte cell design, the separator system typically includes a microporous polyethylene, polymeric PVC or phenolic impregnated polyester separator. It is common for a non-woven glass mat to be attached to this separator. The attached non-woven glass mat is approximately 0.015 inches (0.4 mm) thick and is glued to the ribs of the separator. In assembly, the glass mat faces the positive plate and is used to maintain uniform paste compression, which prevents paste shedding and accumulation in the bottom of the cell. After assembly, the gel is added in its liquid form. Gels, having the property of shear-thinning, are easily liquefied using a high-shear blender or pump. Gels are made by blending fumed or colloidal silica with electrolyte. Gel addition can occur at different stages based on the design and manufacturing approach. The gel can be added prior to formation or it can be added after being formed in a flooded condition. Last, gel can be added to AGM batteries to prevent acid stratification in deep cycling applications or to improve internal/external heat transfer.

PRISMATIC VS. CYLINDRICALVRLA batteries are currently available in many prismatic (rectangular) and cylindrical sizes and shapes.

Prismatic VRLA designs are constructed using conventional flat-pasted plate technology. Prismatic cells are available in many sizes ranging from a few to thousands of amp-hours. The larger cell designs come complete with racks for mounting. In many of the rack-mounted designs, the cells are mounted on their sides for easy access to electrical connections and to minimize stratification of the electrolyte. It also allows the plates to stay in a compressed condition when the separator compression relaxes through dryout. Prismatic shaped batteries are also available in many popular SLI group sizes. These batteries can be used individually in small UPS (uninterruptible power source) cabinets or connected in series for larger standby systems.

Cylindrical VRLA batteries and cells are also available. Cylindrical products are manufactured using spiral-wound cell technology. The large single cells are packaged in a polymer

cylinder with a metal outer wrap and are about the size of a beverage can. SLI 12-volt batteries are also available in a multi-cylindrical-cell molded polymer case. The advantage of the cylindrical design is that there are only two plates per cell that are coiled between two layers of separators. They also maintain a high compression of the plates and separators allowing better cycle life. They also allow superior cooling because of enhanced container surface in all cells. The disadvantage is that the geometry does not permit the optimum use of the volume for power producing materials in comparison with prismatic designs. Cylindrical VRLA cells typically employ AGM separators.

COVER & POST SEALSThe valve-regulated nature of VRLA batteries makes the integrity of the cover and post seals key to the overall cell design. As mentioned earlier, the oxygen recombination process requires that the cell be airtight to maintain either a slight pressure or a vacuum. Ensuring that the container and cover are properly sealed during assembly is extremely critical. Most manufacturers use heat-sealing to facilitate the seal. Then, after the cover is attached, the air-tightness of the cell or battery must be carefully checked for even the smallest leak. Post bushings and seals must undergo the same scrutiny and are checked in the same manner.

The oxygen recombination process requires that the cell remain airtight during its entire life. This means that handling should be done in a way to ensure that the container to cover seal and the post seals are not damaged. VRLA batteries should not be handled roughly or picked up by the posts.

GRID ALLOYSThere are four basic approaches to positive grid alloys: low-antimony / cadmium alloys, low-calcium / high-tin lead alloys, lead-tin alloys and pure lead. Prismatic cell designs tend to use either the low calcium-tin or low antimony / cadmium alloys and in some instances silver is added to the Ca/Sn alloy for added corrosion resistance. The cylindrical cells use soft, flexible pure lead or lead-tin alloys as the grid material and can do so because of their self-supporting spiral wound design. All four general types of grid alloys are claimed to give excellent float life, but some have better cycle life. The alloy used in the negative grid is much less controversial and tends to be a calcium-lead, calcium-tin-lead, or pure lead.

TOP- LEAD ALLOYSFor VRLA designs using a low-calcium, high-tin positive grid, the strap alloy is typically a binary alloy made from lead and tin. Tin levels tend to be 2% or higher. When using an automated cast-on strap cell design, the lugs of the Ca/Sn plates are normally tinned to improve bonding. When hand-burning Ca/Sn plates, the lead-tin alloy is also used but the burn is typically done using a mixing rod to ensure a good burn. Antimonial alloys should not be used for straps with non-antimonial negative plates because of the susceptibility for negative lug corrosion.

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ADVANTAGES & DISADVANTAGES

Minimal GassingVRLA batteries do not typically release gasses like their flooded counterparts. The oxygen recombination process significantly reduces gassing and permits VRLA batteries to be used without the need for special ventilation. These batteries do periodically vent very small amounts of gas and therefore should never be placed in a hermetically sealed cabinet, vault or tightly enclosed space where these gasses could possibly build-up.

No WateringVRLA batteries never need watering. In fact, VRLA batteries should never be opened. The manufacturer has taken great care to seal the cover and vents of the batteries to ensure that the recombination process is maintained. Never open these batteries and never add water or electrolyte.

No Battery Rooms - Reduced VentilationWhen used in traction applications valve-regulated batteries eliminate the need for battery rooms and battery attendants. VRLA traction battery manufacturers indicate that the charging of a VRLA traction battery can be accomplished throughout most warehouses and manufacturing operations.

Spillproof/Leakproof – Flexible Mounting OrientationA major advantage of a VRLA battery is their spillproof/leakproof feature. The thixotropic nature of the gel and the absorbent properties of the AGM separator virtually eliminate spilling and leaking. The spillproof nature of these cells makes it possible to operate these cells standing upright or on their sides. NOTE: Before installing a cell or battery on its side or end, the manufacturer should be consulted. It is not recommended to operate VRLA cells in an upside-down condition.

Reduced Shipping RestrictionsVRLA batteries can be designated as "Batteries, wet, non-spillable" under U.S. hazardous materials regulations and international dangerous goods regulations. Due to the spill-proof and leak-proof features of VRLA batteries, U.S. and international hazardous materials/ dangerous goods transportation regulations provide an exemption to the regulations for these batteries. In order to utilize the exemption, VRLA batteries must meet certain requirements and pass specific Vibration and Pressure Differential Tests. If shipping VRLA batteries in the U.S. under this exception, the package must be marked "NONSPILLABLE" or "NONSPILLABLE BATTERY". Regardless of whether shipping domestically or internationally, VRLA batteries must be shipped in a condition that would protect them from short circuits and be securely packaged to withstand conditions normal to transportation.

There are also certification requirements for the packaging used to ship VRLA batteries.

Depending on the mode of transportation and shipping destination, the following transportation regulations should be consulted prior to shipping VRLA batteries:

• U.S. Code of Federal Regulations Title 49, Section 173.159(d)

• United Nations Recommendations on the Transport of Dangerous Goods Model Regulations, See Special Provision 238

• International Air Transport Association (IATA) Dangerous Goods Regulations, See Special Provision A67 and Packing Instruction 806

• International Civil Aviation Organization (ICAO) Technical Instructions for the Safe Transport of Dangerous Goods by Air, See Special Provision A67 and Packing Instruction 806

• International Maritime Dangerous Goods (IMDG) Code, See Special Provisions 238 and 940

Vibration ResistanceThe construction of a VRLA battery makes these batteries more resistant to vibration. AGM separators are compressed (20-30%) in the cell, thus producing intimate plate to separator contact and resulting in a very tightly packed element. The gel in the gelled battery occupies the spaces between the plates and separators producing an element that has little or no room for plate movement.

CostDue to the additional processing steps, dense cell packing, unique materials, valve design and thick jar/cover walls VRLA batteries are typically more expensive than flooded batteries.

APPLICATIONS

General VRLA batteries can be used in virtually any flooded electrolyte wet cell application as long as the charging system is designed for a VRLA battery. These batteries can also be used in applications where traditional wet cells cannot be used. Care should be taken to locate and arrange batteries where the additional heat associated with the recombination process can be dissipated. Here is a listing of typical applications grouped by the type of usage.

Standby And Emergency Backup ApplicationsIn these standby type applications, the battery is on float charge during its entire life via rectified AC power. The battery is then coupled directly to a DC load or coupled to a DC to AC inverter so it can produce AC power in the event of a power outage. The

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battery is only required to provide energy when the AC power goes out and then operates the device in question such as a computer or telephone system. The service life of the battery is typically limited by the corrosion of the positive grid. The standby battery is discharged infrequently during its life and therefore wear-out of the paste due to cycling is generally not a problem. These batteries usually have thicker positive grids and low-density paste. Typical applications are:

• UPS (Uninterrupted Power Systems)

• Cable TV Backup

• Computer Backup

• Telecommunication Backup

• Emergency Lighting

• RAPS (Remote Area Power Supply)

Accelerated testing is used by battery manufacturers to estimate the life of their products. Since corrosion based failure mechanisms can be accelerated by heat, accelerated battery testing is done at elevated temperatures. Care must of course be taken to ensure that the charging voltage is adjusted to compensate for the elevated temperature. Also, since VRLA batteries are electrolyte starved, effort must be made to ensure that the accelerated testing is done under conditions that will not change the failure mechanism. Testing at too high a temperature or testing in an oven rather than a water bath may change the battery failure from a positive grid corrosion mechanism to a dry-out mechanism. Typical large-format VRLA battery warranties are 5, 10, 15 or even 20 years. See actual manufacturer information for details.

Many standby or back-up power applications require the jar/cover plastic to have an elevated level of flame retardancy. This is based on specific industry (UPS or Telecom) requirements per the governing building and electric codes/standards. A flame retardancy level of V-2 is required for most UPS applications while V-0 is required for most Telecom applications.

Deep Cycle ApplicationsAn application is considered deep cycle if the battery is used in any of the applications listed below. In this type of use, the battery is not subjected to a constant float charge but is normally recharged after use and then removed from the charger. Batteries designed for these applications are typically manufactured using plates having higher density paste. In these applications, the battery is normally discharged more than 50% in each use.

• Marine Trolling

• Fork Lift Trucks

• Electric Vehicles

• Wheelchairs

• Portable Power

• Recreational Vehicles

• Floor Scrubbers

• Golf Cars

• Electronics

The cycle life of a VRLA battery in a deep cycle application is typically a function of the depth of discharge. Simply stated, the more deeply the battery is discharged, the fewer the number of cycles that can be delivered over the life of the battery. Cycle life is a function of plate thickness, paste density and grid alloy, and it is also dependent on the specific manufacturer. Some typical "cycle lives" are shown below. Most recently, some improvements in cycle life have been attributed to higher rate recharge schemes. This subject will be discussed in more detail in the section on charging. The values given below are typical and the battery user should contact the battery manufacturer for specific recommendations on battery selection and charging for the particular application.

Typical Cycle Life Behavior

Depth of Discharge Cycles

100% 200

50% 600

25% 1200

10% 3500

Other Miscellaneous ApplicationsThe following applications for VRLA batteries cannot be readily categorized as either Standby or Deep Cycle. Most are related to on- or off-road starting which is becoming a popular application for the VRLA battery.

• Lawn & Garden

• Marine Starting

• SLI

• Solar Power

• Off-Road Vehicles

• Race Cars

• On-Road Vehicles

• Motorcycles / Scooters

CHARGING CONSIDERATIONS

The Initial ChargeWhen a VRLA battery is installed, it is highly recommended that it be given an initial or freshening charge to replace any charge that was lost during shipment and storage. The initial charge should be conducted using a constant voltage charger that is manufacturer approved (since many chargers have waveforms that are not pure DC). To begin the charging process, the voltage of the charging system must be measured without the

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load connected and then divided by the number of cells to be charged in series. The charging voltage should not exceed 2.35 volts per cell at ambient temperature unless otherwise specified by the manufacturer. Charging time is a function of voltage and battery temperature.

Float ChargingFloat charging is done in order to maintain the battery in a full state of readiness while ensuring maximum battery life and performance. To begin a float charge, one must first establish the string charging voltage. This is done by multiplying the number of cells in the series string by the recommended float voltage for each cell. The recommended float voltage is temperature dependent and may vary by battery manufacturer. An example of a float charge voltage table is shown in Table 1.

TABLE 1

°F °CRecommended

Float Charge Voltage (volts per cell)

25 -4 2.33

35 2 2.33

45 7 2.32

55 13 2.30

65 18 2.28

75 24 2.25

85 29 2.23

95 35 2.21

105 41 2.19

115 46 2.17

125 52 2.17

Using the above table (or a similar table from the manufacturer), the constant voltage should be adjusted to provide the recommended float voltage at the battery terminals. When the cells are new, expect to see variations in float voltage from cell to cell within the string. Variations in cell voltage may be as high as +/-0.1 volts when the cells are new and would be expected to tighten to +/-0.05 when the string is more than 6 months old. VRLA battery users should consult the manufacturer's recommended voltage limits. Using float voltages higher or lower than those recommended may result in reduced battery life and/or reduced capacity.

For optimal battery life and performance, it is recommended that the charger be temperature-compensated. Should the battery temperature change for any reason, the charging voltage will automatically be adjusted upwards or downwards. A charger having remote temperature sensing (on the battery) capability is preferred. Another reason for using a temperature-compensated

remote temperature-sensing charger is to minimize the chances of Thermal Runaway.

Thermal Runaway is a charging-related phenomenon that may occur when the temperature of a battery becomes elevated while charging with a non-temperature compensated charger. For example, if the battery temperature becomes elevated for any reason (such as if the ambient temperature is raised) the charging voltage should be reduced as seen in Table 1. If the charging voltage is not reduced as the battery temperature becomes elevated, the battery will receive a higher degree of overcharge. The higher amount of overcharge will in turn generate even more heat, which will raise the battery temperature even further. As the battery continues to charge in this mode, this imbalance in temperature and charging voltage will cascade and the battery temperature will become extremely high. This condition is referred to as Thermal Runaway and will permanently damage the battery and/or equipment. Instances of Thermal Runaway have even been known to create so much heat that the VRLA battery case will soften and melt. During Thermal Runaway excess gas is produced which is vented along with water vapor. These gasses and vapors may be hazardous to personnel and equipment.

Deep Cycle ChargingWhen deep cycling a VRLA battery there are two charging options: the normal IE charging scheme and the newer IEI charging method. Most VRLA battery manufacturers recommend the IE (constant current - constant voltage) method using initial in-rush charging currents that are approximately the C/3 to C/5 rate. The battery is charged at this current to 2.35-2.40 volts per cell voltage limit (temperature compensated). The battery is then charged at constant voltage until the current drops to a specified value, which is typically less than the C/100 rate. See the specific battery manufacturer's charging recommendations for the exact details.

The IEI scheme, constant current - constant voltage - constant current recharge method has been shown to yield the longest cycle lives by the US Advanced Battery Consortium (USABC). This charging method is similar to the IE charging scheme with the exception that a final constant current phase is added to the sequence. In this phase, the battery is subjected to a final low current C/50 - C/100 charge rate with no voltage limit. Charging is terminated when the battery voltage is stable and changes less than approximately 20 mv/cell/hour. This type of charge is designed to eliminate problems related to undercharge of the negative and to reduce cell-cell imbalance. Some manufacturers may have time limits for use of charge voltages above 2.4 volts per cell.

Boost / Equalize / Freshening ChargeUnder normal conditions for VRLA batteries, an equalizing charge is not required but is used when a non-uniformity has developed between cell voltages in a string or battery. An equalizing charge is given to restore all cells to a fully charged condition. It should be stated that charger malfunctions and cell-to-cell temperature variations may also cause a nonuniformity in cell voltages.

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A battery should be given an equalizing charge if: 1) the float voltage of any one cell is less than 2.17 volts or 2) the float voltage of the cells is outside the +/-0.1 volts of the nominal voltage setting in cells that are older than 6 months. Consult the manufacturer's recommendations for equalizing cells that are less than 6 months old.

To perform an equalizing charge, the constant voltage charging method is recommended. To equalize charge at temperatures between 70-90 °F use 2.32 volts per cell for 24 hours (after current stabilization). At lower temperatures such as 55-69 °F, 2.35 volts per cell may be used. Note: The equalizing charge should be terminated if the temperature of the cell/battery exceeds 105 °F. Failure to do so may damage the cell or battery. Be sure to refer to the manufacturer's Operating Instructions for specifics regarding charging of any VRLA battery.

SAFETY

GeneralUnder NORMAL operating conditions and use, these are some of the design features of VRLA batteries:

• Minimized hydrogen gas release

• Virtually elimination of acid misting

• Elimination of leakage

Under ABNORMAL operating conditions or as a result of damage or abuse, potentially hazardous conditions may occur including:

• Hydrogen gassing

• Acid misting

• Acid leakage

• Thermal Runaway

Equipment and ClothingWhen working with any battery system, always remove jewelry, keep sparks, open flames and smoking materials away and have the necessary tools and equipment available, such as:

• Rubber gloves

• Rubber apron

• Insulated tools

• Fire Extinguisher

• Safety glasses

• Acid spill kit

• Face shield

• Eye wash or shower

All tools should have insulated handles, and you should never lay tools or other metal objects on the battery when working.

INSTALLATION, MAINTENANCE & IN-FIELD DIAGNOSTICS OF VRLA BACKUP SYSTEMS

InstallationVRLA batteries should be installed in a clean, cool and dry environment. Ambient temperature should be between 68°-77° F for maximum battery performance and life. Elevated temperatures reduce battery life, while lower temperatures reduce battery performance. Battery spacing requirements must be followed to ensure adequate air movement and convective heat transfer. Aisle space should meet National Electric Code Article 110-16 or local codes. No special ventilation is required for VRLA batteries, but never install any battery in an airtight enclosure. VRLA batteries may be installed next to electronic equipment. DO NOT LIFT BATTERIES BY TERMINAL POSTS (this may cause air leaks which may affect the oxygen recombination process). When connecting wires and bus bars to the battery, use a torque wrench and do not over tighten the terminals. Anti-oxidizing greases should be used on all terminal connections if recommended. Batteries should be firmly mounted using manufacturer-specified racks or mountings.

MaintenanceThe battery should be examined for cleanliness at regular intervals. Keep cell terminals and connectors free of dust and corrosion. Terminal corrosion may affect the performance of the battery and could present a safety hazard. Should corrosion be observed, disconnect the battery, unbolt and remove the connectors, and remove the corrosion by brushing the terminals and connectors with a dilute solution of baking soda (sodium bicarbonate) and water. Reapply an anti-oxidizing grease before reconnecting and bolting the connectors. Always maintain proper records.

DO NOT UNDER ANY CIRCUMSTANCES REMOVE PRESSURE RELIEF VALVES AND NEVER ADD WATER.

Capacity TestingA capacity test is always used to properly evaluate the performance and condition of a battery. This may or may not be possible during the life of the battery due to the type of service into which the battery is placed. Before beginning a capacity test, one cell (or battery monoblock) is typically selected as the Pilot Cell and is used throughout the life of the battery as an indicator of the overall condition of the battery. As the capacity test is performed, the voltage of the Pilot Cell is monitored along with the voltage of the entire battery.

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Measurement techniques based on the resistance characteristics of the battery can be used to assess the general condition of the battery. Trending of these measurements is more beneficial in understanding the battery state of health than a single measurement. More recently, methods have been introduced that use the inverse measurement, called Conductance, which more directly trends with battery capacity. There have been many recent publications discussing the feasibility for predictive use of these ohmic measurements.

Cell Voltage DistributionThe distribution of the cell float voltages can typically be used to diagnose the condition of the cells in a battery string. In general, it is recommended that string cell voltages be within +/- 0.10 volts of each other. Especially in cells that have been in service for more than 6 months, cell voltages should be relatively uniform (see manufacturer's recommendations). While on float charge, a cell that is significantly less than 2.17 volts (13.02 volts for a 12-volt battery) is a sign of a potential problem. The string should be given an equalizing charge and the suspect cell should be monitored closely. A capacity test may be done to properly establish the condition of the battery.

State Of Charge DeterminationThe design of a VRLA battery makes it impossible to directly measure specific gravity (S.G.) and therefore the S.G. cannot be used to establish the State of Charge (SOC) in the conventional manner. The SOC of a VRLA battery can be estimated in the following three ways:

(1) The SOC can be estimated from the Open Circuit Voltage (OCV) of the cell in the following manner. Remove the cell (or battery) from any charger or load and permit the cell to stand at Open Circuit for at least 8 hours (preferably 24 hours). The S.G. (Specific Gravity) is directly related to the OCV and can be estimated from the OCV by the equation: S.G. = OCV - 0.840. The SOC can then be estimated from the Specific Gravity as shown below, but this relationship will vary based on S.G. specifications of each manufacturer and active material to electrolyte ratios of each individual battery type as well as the capacity loss that the battery has sustained.

SOC% S.G. OCV

100 1.300 2.14

75 1.260 2.10

50 1.220 2.06

25 1.160 2.00

0 1.130 1.97

(2) SOC measurement techniques based on the conductance or resistance characteristics of the battery can be used. For details, contact the manufacturers of ohmic test equipment.

(3) When performing a constant voltage recharge, the battery is recognized as being fully charged when the current has tapered down and remains at a relatively constant value for more than 3 hours.

Sidewall Bulge & Sidewall DishingIn order for the oxygen recombination reaction to proceed efficiently, VRLA batteries will generally operate under a positive pressure while in use. The pressure level is managed by a pressure relief valve, which is integral to the battery. Because of this, some slight bulging of the side and end walls may be noticed. On batteries left in storage, a slight vacuum may actually be created in the cell causing some end wall dishing. This occurs as a result of the natural recombination of oxygen at the negative plates and the diffusion of small amounts of hydrogen out of the battery through the polymer case.

Excessive side or end wall bowing may indicate an inoperative vent or a problem with the charging system, which leads to overheating of the battery. Please consult the battery manufacturer for advice.

Cover Bulge & Post TiltingCover bulge and post tilting are indications of serious problems with your VRLA battery. Both of these phenomena are the result of positive plate grid growth. In the event that a significant amount of cover bulging or post tilting is observed, please consult the manufacturer for advice.

Ohmic Measurements

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INDEX

AAcid, Sulfuric (See Electrolyte) Activation Damp Dry .........................................................................33 Dry Charged ...............................................................33, 37 Alternator..............................................................................49 Ampere (Amp) ....................................................................... 1 Ampere-Hour (AH) ...............................................................1 Automatic Chargers .............................................................43 Automotive Charging Systems............................................49

BBattery Capacity........................................................................1, 34 Carrier ...............................................................................36 Chemicals Used In .............................................................6 Construction ............................................................... 12-17 Defined ............................................................................... 6 Electrochemical Action ..................................................... 6 Explosions .............................................................. 4, 39-40 Freezing ......................................................................10, 32 How It Operates ................................................................. 6 Installation ............................................................ 22, 34-38 Purpose Of.......................................................................... 6 Ratings..............................................................................30 Seals ..................................................................................15 Storage........................................................................28, 32 Battery, Common Terms ....................................................1-3 Battery Hookups...................................................................42 Battery Testing Golf Car, Deep Cycle Marine and Other Cycling Batteries ............................................ 26-27 Starting Batteries........................................................ 21-25 Boost Charge ...................................................................1, 33 Booster (Jumper) Cables .............................................. 39-40 Buckled Plates ......................................................................46

CCables....................................................................................37 Cable Clamp Spreader .........................................................35 Cable Puller (Tapered Terminal) .................................. 34-35 Carrier, Battery.....................................................................36 Causes of Failure...................................................... 23, 44-48 Cell Connectors....................................................................15 Charge Current Acceptance..................................... 41, 50-51 Effect of Temperature................................................ 50-51 Charged & Wet Batteries.....................................................19 Charging, Batteries ...........................27, 41-43, 49-51, 55-58 Boost Charge..............................................................33, 56 Calculating Recharge.................................................27, 41 Charging Guide Constant Voltage..............................................................43 Taper Current Charge ......................................................43 Constant Current Slow Charge .......................................43 Fast (High Rate) Charge..................................................43 Trickle Charging ..............................................................43 VRLA Batteries ......................................................... 55-58

Chemical Action On Charge...........................................................................7 On Discharge......................................................................6 Code, Dates...........................................................................45 Cold Cranking Performance Ratings ..........................................................................1, 30 Effect of Temperature and Oil ........................................30 Effect of State-of-Charge ................................................30 Common Battery Terms......................................................1-3 Conductance Testing............................................... 22, 25, 58 Container(Case)....................................................................15 Cover.....................................................................................15 Cover Bulge, VRLA Batteries.............................................58 Cover Vent Wells.................................................................15 Curing (Chem-set)...........................................................13,19 Current Acceptance.................................................. 41, 50-51 Current, Alternating (AC) ................................................................1 Direct (DC).........................................................................1 Current Loads, Vehicle ..........................................................7 Cycle ............................................................................... 1, 6-7

DDamage, Claim For ..............................................................31 Damp Dry Batteries ................................................ 20, 33, 36 Date Coding..........................................................................45 Deep Cycle Applications ...............................................26, 55 Determining Causes of Battery Failure .................. 23, 44-48 Diodes ...................................................................................49 Discharge, Battery..............................................................1, 6 Dry Charged Batteries........................................20, 33, 36-37

EGolf Car, Deep Cycle Marine and Other Cycling Batteries ............................................. 26-28 Charging ..................................................................... 27-28 Testing ..............................................................................27 Electrolyte (Sulfuric Acid) ...................................1, 4-5, 8-10 Discoloration ....................................................................45 Freezing Points...........................................................10, 32 Levels..........................................................................22, 37 Mixing......................................................................... 4-5, 8 Element ...................................................................................2 Construction .....................................................................13 Examination ............................................................... 45-48 Rests (Bridges) .................................................................15 Expanders .......................................................................13, 18 Explosions, Battery ...........................................4-5, 39-40, 41

FFilling Devices .....................................................................34 Flame Arresters ....................................................................16 Formation.................................................................... 2, 19-20 Freezing of Electrolyte...................................................10, 32

GGasses, Explosive.......................................................4, 39, 41

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Gassing, On Charge .........................................................7, 21 Gelled Electrolyte Battery (Gel Cell) ........................... 52-53 Generator, DC ......................................................................49 Golf Car, Deep Cycle Marine and Other Cycling Batteries ............................................. 26-28 Gravity, Specific ..................................................... 2,8-10, 22 Grid ...................................................................... 2, 12, 18, 46 Alloys..........................................................................18, 53 Corrosion ..........................................................................46 Grid Types Cast ...................................................................................12 Expanded Metal ...............................................................12 Punched ............................................................................12 Ground .................................................................................... 2 Groups, Plate ........................................................................14

HHigh Rate (Fast) Charging...................................................43 High Rate Discharge (Load) Test ........................... 21-22, 24 History of the Battery ..........................................................44 Holddown ....................................................................... 37-38 How A Battery Works ......................................................6-10 Hydrogen Gas..................................................................4-5, 7 Hydrometer................................................................... 2, 8-10 Hydrometer Test............................................................. 21-22 Hydroset – Curing...........................................................13,19

IImpurities..........................................................................8, 45 Inspecting Shipments...........................................................31 Installation, ..................................................................... 37-38 VRLA Batteries ...............................................................57 Intercell Connections ..................................................... 14-15 Internal Examination of Battery.................................... 46-48

JJump Starting.................................................................. 39-40

LLead Alloy .................................................................................12 Dioxide ................................................................6-7, 15-16 Oxide ....................................................................13, 15, 18 Sponge ...................................................................... 6-7, 16 Sulfate..............................................................................6-7 Load Test .................................................................. 21-22, 24 Starting Batteries Charging ..................................................................... 41-43 Description .......................................................................21 Installation .................................................................. 37-38 Stock Maintenance..................................................... 32-33 Testing ........................................................................ 21-25 Lugs, Plate ............................................................................12

MManufacturing Processes............................................... 18-20 Mixing Electrolyte ..............................................................4-5 Mossing.................................................................................46

NNegative.................................................................................. 2

Negative Plates ........................................................... 6, 12-13 Examination Of ................................................................47 Neutralizing Spilled Acid ......................................................4 New Battery Installation ................................................ 34-38

OOhm.........................................................................................2 Ohmic Measurements ............................................. 22, 25, 58 Open Circuit Voltage ............................................ 2, 9, 24, 29 Overcharging ...............................7, 21, 27, 43, 44-47, 50, 56 Oxide (see Lead Oxide) Oxygen Gas ........................................................................4, 7 Oxygen Recombination .......................................................52

PParallel Connection ..............................................................42 Paste Mixing .........................................................................18 Plates Examination Of ...........................................................52,53 Grids............................................................................12, 18 Groups...............................................................................14 Negative............................................................6, 12-13, 47 Paste ...................................................................... 12-13, 18 Pasting...............................................................................18 Positive .............................................................6, 12-13, 46 Strap ............................................................................ 14-15 Positive....................................................................................2 Pre-Installation Testing.................................................. 37-38 Preparation of New Batteries Damp Dry .........................................................................36 Charged and Wet..............................................................37 Dry Charged .....................................................................37 Purpose of the Battery............................................................6

RRacks, Storage ......................................................................32 Recombination......................................................................52 Regulation....................................................................... 50-51 Regulator......................................................................... 49-50 Removing Old Battery .........................................................37 Reserve Capacity Rating..................................................2, 30 Resistance ...............................................................................2 Resistance Testing................................................... 22, 25, 58

SSafety Precautions........................................................ 4-5, 57 Charging a Battery ................................................... 4-5, 41 Danger of Exploding Battery .................................. 4-5, 41 Handling Battery Acid....................................................4-5 Jump Starting an Engine............................................ 39-40 Sandy Negative Material .....................................................47 Sediment Space ....................................................................15 Selecting Battery Size ..........................................................36 Self-Discharge ......................................................................33 Separators ....................................................... 2, 13-14, 47-48 Series Connection.................................................................42 Service Procedures ...............................................................39 Servicing Battery in Vehicle ......................................... 39-40 Servicing Tools............................................................... 34-36 Shipping Restrictions .....................................................31, 54 Shorts ........................................................................... 2,45-48 Side Terminals................................................................17, 38

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Side Terminal Ratchet Wrench ...........................................38 Sidewall Bulge & Dishing...................................................58 Specific Gravity ..................................................... 2, 8-10, 22 Temperature Correction................................................9-10 Tropical and Arctic Climates ..........................................10 Spillproof ..............................................................................54 Standby Applications..................................................... 54-55 State-Of-Charge ................................... 2, 8-10, 21-22, 27, 58 Stock Maintenance......................................................... 32-33 Damp Dry .........................................................................33 Dry Charged Batteries .....................................................33 Charged and Wet Batteries........................................ 32-33 Stock Rotation ......................................................................32 Storage, Batteries .................................................................32 Sulfate ...............................................................................6, 46

TTemperature, Effect on Charge Acceptance................. 50-51 Temperature Compensation ................................................51 Temperature Correction – Specific Gravity .......................10 Terminal Cleaner (Tapered Terminal) ................................35 Terminal Designs “L” Terminal .............................................................. 16-17 Side Terminal ............................................................. 16-17 Stud Terminal............................................................. 16-17 Tapered (Top) Terminal ..................................................16 Testing Charts Golf Car, Deep Cycle Marine and Other Cycling Batteries ...................................................29 Starting Batteries........................................................24, 25 Tests, Battery Golf Car, Deep Cycle Marine and Other Cycling Batteries ............................................. 26-28 Starting Batteries........................................................ 21-25 Thermometer .....................................................................9-10 Top-Lead Alloys ..................................................................53

Torque Values (Cables, Holddowns)............................ 37-38 Trickle Charging ..................................................................43 Tropical Climate, Specific Gravity .....................................10

UUndercharging .................................................................46,51

VVehicle Current Loads ...........................................................7 Vent Caps..............................................................................16 Flame Arrester..................................................................16 Vibration ...............................................................................54 Visual Inspection............................................... 21, 22, 39, 44 Volt..........................................................................................3 Voltage Battery.............................................................................6, 9 Cell ......................................................................................6 Charging ...............................................................41-43, 50 Open Circuit Voltage.........................................................2 Stabilized ..........................................................................22 Voltage Regulator .......................................................... 49-50 Voltmeter Check ............................................................22, 24 VRLA Batteries.............................................................. 52-58

WWarning, (Electrolyte, Explosive Gases)................................................ 4-5, 41, 57 Water Approved ............................................................................8 Loss Of .............................................................................21 No Watering ...............................................................21, 54 Watt .........................................................................................3 Wet Battery Stock Maintenance.................................... 32-33 Wrenches ........................................................................34, 38