Characterisation of FIAMM SMG Solar PRODUCT …batteryaustralia.com.au/wp-content/uploads/2014/12/Fiamm... · Industrial Batteries Characterisation of FIAMM SMG Solar product range

REV. DATE PREPARED BY APPROVED BY

0 12/11/02 M. MION G. LODI

Industrial Batteries

Characterisation of

FIAMM SMG Solar PRODUCT Range

According to BS 6290 : Part 4: 1997


Characterisation of FIAMM SMG Solar product

range according to BS 6290:Pt 4 1997

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1. Introduction...................................................................................................................3 1.1. Major symbols ...........................................................................................................3 1.2. Foreword...................................................................................................................3 1.3. Test Programme .......................................................................................................4

2. Electrical performance ..................................................................................................5 2.1 Capacity level test .....................................................................................................5

2.1.1 Major symbols used for the determination of the capacity level .........................5 2.1.1. Capacity test ......................................................................................................6 2.1.2 Correction factor ................................................................................................7

2.2. Cyclic endurance test................................................................................................8 2.2.1. Cycle test ...........................................................................................................8 2.2.2. Cyclic endurance result......................................................................................9

2.3. Charge retention test...............................................................................................11 2.4. Internal resistance...................................................................................................12

2.4.1. Internal measurement test procedure ..............................................................12 2.4.2. Internal resistance test results .........................................................................12

3. Durability tests ............................................................................................................14 3.1. Elevated temperature test .......................................................................................14

3.1.1. Test procedure.................................................................................................14 3.2. Float voltage characteristics....................................................................................18

3.2.1. Test procedure.................................................................................................18 3.3. Pillar seal assembly ................................................................................................23 3.4. Mechanical strength ................................................................................................24

3.4.1. Test procedure.................................................................................................24 3.4.2. Test results ......................................................................................................24

4. Safety features ...........................................................................................................25 4.1. Terminal pillars........................................................................................................25 4.2. Container and lids ...................................................................................................25

4.2.1. Flammability of plastics....................................................................................25 4.2.2. Container integrity............................................................................................25

4.3. Gas emission ..........................................................................................................26 4.3.1. Major symbols..................................................................................................26 4.3.2. Collecting and measurement devices ..............................................................26 4.3.3. Test Report ......................................................................................................26

4.4. High current endurance...........................................................................................28 4.4.1. High current test procedure..............................................................................28 4.4.2. High current test result .....................................................................................29

Appendix A: Charging procedure.......................................................................................30




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1. Introduction

1.1. Major symbols The major symbols used in this report are indicated in Table 1.

Symbol Meaning Ck Rated capacity

Cak Actual capacity at rate k EDV End of discharge voltage Vpc Volt per cell

Table 1, Major symbols

1.2. Foreword This document reports the results of type tests on the FIAMM SMG Solar range as required by BS6290 Part 4: 1997. The letter “S” behind each battery model would denote it is from the SMG Solar range, for example SMG1500S. The FIAMM SMG Solar range is a homogeneous set of products in terms of design and manufacturing characteristics. More precisely they employ the same materials, manufacturing processes, design features and quality systems. According to this, one type was selected as representative of the entire product range. This type is the SMG1500S battery (2 Volts, 1500 Ah) being it one of the largest batteries in terms of capacity and voltage. Due to the very high current required in some the tests it was chosen the SMG800S battery type for the cyclic endurance test and internal resistance test. For the same reason it was chosen the SMG200S type for the high current endurance test and for the pillar seal assembly test. Due to mechanical reason it was chosen the SMG200S for the mechanical test. The results of the tests reported in this characterisation can therefore be generalised to the entire FIAMM SMG Solar range.




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1.3. Test Programme A group of 42 SMG Solar batteries were taken from production and used for the various type tests. The batteries were numbered from 1 to 42 and they were grouped as indicated in Table 2.

Test type Unit identifying

number Type of battery

Capacity test 1-6 SMG1500S Gas emission 1-6, 37-42 SMG1500S Cyclic endurance 13-18 SMG800S Internal resistance 13-18 SMG800S Life at elevated temperature 19-22 SMG1500S

Float voltage characteristics 23-28 SMG1500S Mechanical strength 29-31 SMG200S Pillar seal assembly 32-33 SMG200S High current endurance 34-36 SMG200S Charge retention 37-42 SMG1500S

Table 2, Test Programme

Unless otherwise specified, the test procedures and equations/formulas to calculate the qualifying parameters of each test adhere strictly to the requirements of BS 6290: Part 4.




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2. Electrical performance

2.1 Capacity level test

2.1.1 Major symbols used for the determination of the capacity level

Table 3 shows the major symbols used for the determination of the capacity level.

Symbol Meaning

Ck Capacity at a discharge rate of k hours r Rate of discharge θt Test temperature rI Current value estimated by manufacturer Uf Final end voltage rt Measured durations of the discharge at the specified Uf voltage rtθ Durations value corrected for the temperature θt





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2.1.1. Capacity test

Six units SMG1500S were subjected to the capacity level test. The units were identified with numbers 1-6. The current rI was estimated by the manufacturer for every rate of discharge r (as reported in Table 5). Table 5 shows the current values rI and the measured discharge duration rt (in hours). Table 6 shows the mean test temperature θt. The final end voltages per cell Uf considered in Table 5 are summarised in Table 4.

Discharge rate (h)

Uf (Vpc)

10 1,8 8 1,8 3 1,8 1 1,8

0,25 1,8

Table 4, Uf against discharge rate

Unit 1 Unit 2 Unit 3 Unit 4 Unit 5 Unit 6 Discharge rate

(h) rI

(A) rt (h)

rt (h)

rt (h)

rt (h)

rt (h)

rt (h)

10 103 12,5 12,7 12,5 12,7 12,5 12,6 8 123 9,8 9,7 9,8 9,9 9,8 9,7 3 253 4,0 3,8 4,0 4,0 3,8 3,8 1 461 1,52 1,62 1,70 1,67 1,62 1,54

0,25 715 0,63 0,76 0,65 0,73 0,62 0,65

Table 5, Measured discharge duration rt

Discharge rate

(h) Mean test

temperature, θt (°C)

10 19,2 8 20,3 3 21,4 1 23,2

0,25 22,2

Table 6, Mean test temperature θt




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2.1.2 Correction factor

The durations rt were corrected for the temperature as per BS6290: Part 4:

rtθ = rt / (1 + 0.006 · (θt – 20 ) ) This correction procedure was applied to all durations rt, the results are reported in Table 7.

Unit 1 Unit 2 Unit 3 Unit 4 Unit 5 Unit 6

Discharge rate (h)

rI (A)

rtθ (h)

rtθ (h)

rtθ (h)

rtθ (h)

rtθ (h)

rtθ (h)

10 103 12,6 12,8 12,6 12,8 12,6 12,7 8 123 4,7 4,6 4,7 4,7 4,7 4,6 3 253 4,0 3,8 4,0 4,0 3,8 3,8 1 461 1,49 1,59 1,67 1,64 1,59 1,51

0,25 715 0,62 0,75 0,64 0,72 0,61 0,64

Table 7, Discharge duration rtθ corrected for temperature




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2.2. Cyclic endurance test The cyclic endurance test was performed on six SMG800S units numbered 13-18. The six units were subjected to an initial discharge at the 3 h rate at 1.80 Vpc. All the batteries delivered more than 100% of the rated value (see Table 8).

Unit Number Capacity

at the 3 hours rate (Ah)

Capacity at the 3 hours rate

(% of nominal) 13 700 119% 14 717 122% 15 688 117% 16 706 120% 17 694 118%

18 700 119%

Table 8, Initial discharge at the 3h rate

2.2.1. Cycle test

The discharge scheme adopted in this test was as follows: 1) a discharge for 3 h at a current of I = 151 A (75 % of I3) maintained constant within

± 1 %; 2) a charge for 21 h with a maximum current of 250 A and a maximum voltage of 2.4 Vpc. During the test, which had a rate of one cycle per day, the room temperature was maintained between 15 °C and 25 °C. After every 50 cycles, the units were removed from the cyclic device and recharged according to the manufacturer’s recommendation (see Appendix A). On completion of the charge, the units were subjected to a discharge at the 3-hour rate. The units were subjected to another series of 50 cycles, and the entire procedure was repeated until the actual mean capacity fell to less than 0.8 · C3.




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2.2.2. Cyclic endurance result

Cycle number Mean capacity

at the 3 hours rate (% of nominal)

1 120% 51 122%

101 123% 151 121% 201 117% 251 114%

301 113% 351 112% 401 111% 451 110% 501 108% 551 102% 601 97% 651 95% 701 94% 751 93% 801 93% 851 92% 901 92% 951 91% 1001 91% 1051 90% 1101 90% 1151 89% 1201 89% 1251 88% 1301 88% 1351 87% 1401 85% 1451 84% 1501 83%

1551 82% 1601 80% 1651 70%

Table 9, Mean capacity in 3 h The mean cyclic duration can be derived from the intersection of the 0.8·C3 value with the curve of actual capacity against cycle endurance. The mean cyclic endurance is of about 1601 cycles.




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Figure 1, Mean capacity versus cycle number




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2.3. Charge retention test Six SMG1500S units identified with numbers 37-42 were subjected to the charge retention test. The units delivered a capacity Ca greater than C3 at 1,8 Vpc. The units were allowed to remain without a connected circuit for a period of 90 days, during which time the average ambient temperature was maintained at 20 ± 2 °C. After 90 days of storage the units were subjected to a 3 h rate discharge to an 1.8 Vpc and they delivered a capacity C’a . The retained charge, CR, expressed as a percentage and calculated with the following equation CR = (100 C’a) / Ca. The delivered capacity in these conditions (C’a) and the retained charge amount are reported in Table 10.

Unit 37 Unit 38 Unit 39 Unit 40 Unit 41 Unit 42 Ca (Ah) 1336 1369 1314 1347 1325 1314 C’a (Ah) 1298 1315 1261 1304 1280 1267

CR (% of rated) 97,2 96,1 96,0 96,8 96,6 96,4

Table 10, Delivered capacity C’a and retained Charge amount (CR)




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2.4. Internal resistance Due to the high currents involved in this test it was necessary to choose a battery with a capacity lower than the SMG1500S. The test was therefore performed on six SMG800S units numbered 13-18. The units were subjected to the 3 h rate discharge to 1.8 Vpc and they delivered a capacity Ca3 higher than the rated capacity. The discharge results are reported in Table 11.

Unit 13 Unit 14 Unit 15 Unit 16 Unit 17 Unit 18 Ca (Ah) 729 747 717 753 747 723

Ca (% of rated) 121 124 119 125 124 120

Table 11, Actual capacity at the 3h rate discharge

2.4.1. Internal measurement test procedure

The units were maintained at an ambient temperature of 20 ± 2°C. The discharge characteristic U=f(I) was determined by using two points in the following way: a) First point, (U1,I1): after 20 s of discharge at the current I1 = 3 · I3 ± 10 %, voltage U1 and

current I1 were recorded to give the first point. The discharge was then interrupted after 20 s. After an open circuit stand of 3 minutes the second point was determined.

b) Second point, (U2,I2): after 5 s of discharge at the current I2 = 9 · I3 ± 10 %, voltage U2 and current I2 were recorded to give the second point.

The slope of the characteristic U=f(I) given by the following equation:

Ri = (U1 - U2) / (I2 – I1)

determines the value of the internal resistance (Ri). The voltage was measured at the terminal of each unit in order to ensure that no external voltage drop would interfere with the test.

2.4.2. Internal resistance test results

The values of currents and voltages and internal resistance of each unit are summarised in Table 12.




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U1 Unit 13

U1 Unit 14

U1 Unit 15

U1 Unit 16

U1 Unit 17

U1 Unit 18 I1 = 660 A

1,736 1,787 1,781 1,771 1,783 1,761 U2

Unit 13 U2

Unit 14 U2

Unit 15 U2

Unit 16 U2

Unit 17 U2

Unit 18 I2 = 1843 A 1,291 1,318 1,304 1,310 1,307 1,305

Internal resistance Ri (mΩ) 0,376 0,396 0,403 0,400 0,402 0,385

Table 12, Currents, voltages and internal resistance for units 13-18




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3. Durability tests

3.1. Elevated temperature test The SMG1500S units subjected to the elevated temperature test are identified with numbers 19-22.

3.1.1. Test procedure

- the units were charged at a float voltage of 2,23 V per cell; - the units were subjected to a discharge test at the 3 h rate. The units were initially subjected to a 3 hour discharge rate to 1,8 Vpc. Each unit delivered a capacity Ca3 higher than the rated capacity. Table 13 shows the achieved actual capacity at 3 h discharge rate corrected with temperature.

Capacity, Ca3

Unit 19 Unit 20 Unit 21 Unit 22 1259 Ah 1325 Ah 1347 Ah 1358 Ah 115 % 121 % 123 % 124 %

Table 13, Actual capacity at 3 h discharge rate corrected with temperature, EDV 1,8 Vpc

The units were subjected to a capacity test at the 1 h rate to 1.75 V per cell. The units were fully recharged and then subjected to a capacity test at the 8 h rate to 1.84 V per cell. The results are reported in Table 15 and Table 16 at day 1. The cycle test was the following: 1) the units were placed in a hot air enclosure. The average air temperature surrounding

the units was maintained at 55 ± 2°C for a period of 42 days. During this period the units were float charged at 2,23 V per cell;

2) after 42 days the units were cooled to normal ambient conditions; 3) the units were subjected to a capacity test at the 1 h rate to 1.75 V per cell. The units

were fully recharged; 4) the units were subjected to a capacity test at the 8 h rate to 1.84 V per cell. The procedure specified at points 1-4 was repeated until the actual capacity fell to less than 0.8 · Cr, the claimed rated capacity at the appropriate rate of discharge. Table 14 shows the rated capacity at 1 h discharge rate to 1.75 Vpc, and the rated capacity at 8 h discharge rate to 1.84 Vpc.




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Discharge rate Rated capacity

1 h at 1,75 Vpc 704 Ah 8 h at 1,84 Vpc 1376 Ah

Table 14, Rated capacity at 1 h discharge rate to 1.75 Vpc and 8 h discharge rate to 1.84 Vpc

Table 15 shows the delivered capacity by units 27-30 at 1 h discharge rate.

Days on float

Discharge number

Unit 19 Unit 20 Unit 21 Unit 22

1 1 125 128 133 134 43 2 131 136 137 137 85 3 131 138 138 140

127 4 134 135 137 139 169 5 128 130 133 133 211 6 127 130 132 132 253 7 116 123 119 121 295 8 101 104 106 110 337 9 86 89 93 97 379 10 69 75 78 82

Table 15, Percentage discharge capacity at 1 h rate against days on float charge at 55°C

Table 16 shows the delivered capacity by units 27-30 at 8 h discharge rate.

Days on float

Discharge number

Unit 19 Unit 20 Unit 21 Unit 22

1 1 114 121 121 123 43 2 119 124 123 124 85 3 121 124 125 127

127 4 119 122 123 125 169 5 116 119 121 122 211 6 110 114 114 116 253 7 107 111 112 114 295 8 103 106 107 108 337 9 97 100 101 103 379 10 90 89 92 94 421 11 72 76 75 79

Table 16, Percentage discharge capacity at 8 h rate against day on float charge at 55°C




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Discharge at 1h rate

0%

20%

40%

60%

80%

100%

120%

140%

160%

0 50 100 150 200 250 300 350 400

Days

Pe

rce

nta

ge

ca

pa

cit

y

Figure 2, Capacity evolution (average of four cells) during accelerated life test. Discharge rate: 1 h

Discharge at 8h rate

0%

20%

40%

60%

80%

100%

120%

140%

0 50 100 150 200 250 300 350 400 450

Days

Pe

rce

nta

ge

ca

pa

cit

y

Figure 3, Capacity evolution (average of four cells) during accelerated life test. Discharge rate: 8 h




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Table 17 shows the average endurance at both discharge rates.

Discharge rate Average endurance

(days at 55 °C) BS average endurance

classification

1 h 368 368/1/2,23 8 h 410 410/8/2,23

Table 17, Average endurance at 55 °C




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3.2. Float voltage characteristics The float voltage test was carried out on six SMG1500S units identified with numbers 23-28. The value of float voltage Uflo considered in the test is 2,23 V per unit.


The ambient temperature was maintained at 20 ± 1 °C. day 1: the units were placed on permanent floating charge at 2,23 V. day 8: the units were discharged at 3 h rate with an end of discharge voltage of 1,7 V

and then returned to permanent floating charge at 2,23 V; day 11: the units were discharged at 3 h rate with an end of discharge voltage of 1,7 V

and then returned to permanent floating charge at 2,23 V; day 91: the units were discharged at 3 h rate with an end of discharge voltage of 1,7 V

and then returned to permanent floating charge at 2,23 V; day 183: the units were discharged at 3 h rate with an end of discharge voltage of 1,7 V. Table 18 shows the unit float voltage measurements prior to the discharges 1,3 and 4.

Day Discharge number

Unit 21 (V)

Unit 22 (V)

Unit 23 (V)

Unit 24 (V)

Unit 25 (V)

Unit 26 (V)

8 1 2,232 2,219 2,212 2,205 2,235 2,218 11 2 2,228 2,217 2,214 2,206 2,230 2,220 91 3 2,224 2,230 2,235 2,215 2,241 2,218 183 4 2,229 2,234 2,236 2,214 2,239 2,214

Maximum float voltage 2,241 +1 % Minimum float voltage 2,205 -1 %

Table 18, Voltage measurements prior to the discharges 1, 3 and 4

The maximum and the minimum float voltage measurements were within the range Uflo ± 3%. For this reason the six units passed the float voltage test. Table 19 shows the actual C3 capacities for the six units at day 8, 11, 91 and 183. Discharge

number day

Unit 21 (Ah)

Unit 22 (Ah)

Unit 23 (Ah)

Unit 24 (Ah)

Unit 25 (Ah)

Unit 26 (Ah)

1 8 1428 1438 1448 1403 1452 1389 2 11 1442 1450 1448 1415 1437 1400

3 91 1439 1425 1429 1429 1445 1390 4 183 1412 1419 1426 1396 1430 1367

Table 19, Actual capacities corrected with temperature




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Table 20 shows the maximum unit variation from the initial discharge (day 8).

Unit 28

Initial capacity Final capacity 1389 Ah 1367 (-2%) Ah

Table 20, Maximum unit reduction

The following figures show capacity evolution for each unit (3 h rate to 1.7 Vpc).




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Float voltage test - Unit 23

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Figure 4, Unit 23: capacity at days 8, 11, 91 and 183


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3.3. Pillar seal assembly Because of the specific construction characteristics of the SMG Solar series, we performed the adhesive seals test to verify the pillar seal assembly features instead of the compression seal test. Due to dimensional and weight problems, this test was carried out on two SMG200S units identified with numbers 32-33. The climatic enclosure used in this test was an Angelantoni Climatic Systems that is capable of control temperature from –40 °C to +180 °C and humidity from 0 to 95 %. The units were given a constant current of 4.9 A (0.033 · C3) and they were subjected to 24h cycles of the temperature conditions shown in Figure 5.

-20

-10

0

10

20

30

40

50

60

70

0 5 10 15 20

Hours

Tem

pera

ture

(°C

)

Figure 5, Temperature-time cycle

The humidity was maintained from 90 % to 95 % when the temperature was between 25 °C and 65°C. This cycle was performed 10 times and then the external surfaces of the positive and the negative terminal pillars were inspected for the presence of acid. No acid was detected after the first ten cycles and the 10 days cycle was repeated eight times. After the cycles the units were checked and no signs of leakage were detected, for this reason the batteries numbered 32-33 passed the test.




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3.4. Mechanical strength The test was carried out on three SMG200S units identified with numbers 29-31. The units were checked to be leak proof before the tests to a positive pressure of 30 kPa.


a) The three units were checked to be leak proof before the tests to a positive pressure of

30 kPa; b) Each unit was discharged at 5 minutes rate with an end of discharge voltage of

1.62 Vpc; c) Each unit was tested in accordance with BS-EN 60068-2-6. The units were maintained

in an upright position and then they were vibrated an initial amplitude of 6 mm (peak to peak) in three phases trough 5 Hz to 150 Hz, with a crossover frequency 13 Hz at 1 octave per minute for 30 minutes in each plane;

d) Each unit was tested in accordance with BS-EN 60068-2-32. They were dropped twice on its base onto a solid floor from a height of 100 mm;

e) Each unit was discharged at 5 minutes rate with 1.62 Vpc end of discharge voltage.

3.4.2. Test results

The units remained gas and liquid tight at the end of the mechanical test. The discharge of the units in 5 minutes delivered a capacity greater than 90 % of the initial value, so they passed the mechanical tests.




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4. Safety features

4.1. Terminal pillars The terminal pillars are cast in lead and contain a threaded female insert to which electrical connections can be made. The covering of lead round the insert within the unit is more than 2 mm.

4.2. Container and lids

4.2.1. Flammability of plastics

The containers and lids of the SMG Solar range are made of standard ABS materials. Upon request we can provide the complete SMG Solar range made of flame retardant plastics materials. Flame retardant lids and containers were tested in accordance with UL-94 Standard: “Vertical burning test for classifying materials 94V-0” (point n°3). Lids and containers for SMG Solar range have obtained 94V-0 classifications.

Flammability of plastic according to

UL-94 Standard Standard cell HB

Flame retardant cell 94V-0

Tabella 26 Flammability of plastic

4.2.2. Container integrity

The containers and lids are designed to minimize flexing of the surfaces under normal internal operating pressures, and operating temperatures up to 40 °C. The lid is welded to the container. The complete assembly, which includes the pillar to lid seal, is capable of withstanding an internal pressure of five times the declared mean venting pressure at 1 litre per minute without fracture for 5 h at 20 °C.

Mean venting pressure 12,3 kPa Test pressure 60 kPa

Table 27, Mean venting pressure and test pressure




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4.3. Gas emission

4.3.1. Major symbols

The major symbols used in this test are given in Table 28.

Symbol Meaning Dimension

Va Actual volume of gas collected m3 Ta Ambient temperature °C Pa Ambient pressure bar VN Normalised volume of gas m3

TR Reference temperature K GE Normalised gas emission rate m3 / (Ah · h)


4.3.2. Collecting and measurement devices

The collecting devices are transparent plastic bags impermeable to gases. Each battery was connected to a collecting device. The determination of the exact gas amount contained into the bags was obtained by using a burette measuring system.

4.3.3. Test Report

The test was carried out on twelve SMG1500S cells identified with numbers 1-6 and 37-42 for a total of 12 cells. The units were found to have a capacity Ca greater than C3. The cells were maintained at a temperature between 20 °C and 25 °C. Each cell valve cover was fitted with a gas collection device with a volume accuracy of ± 1 %. The cells were charged at 2,4 V per cell for 72 h. On completion of 72 h of float charge, gas collection started and continued for a further 96 h. Table 29 reports the cumulative total actual volume of gas collected (Va) for four cells over the period of 96 h, the ambient temperature Ta and the pressure Pa.

Va (m3) Ta (°C) Pa (bar)

0,0888 22,4 0,96

Table 29, Gas emission data




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The normalised volume of gas, VN, emitted by the units at 20 °C and 1 bar pressure, is given by the following equation:

VN = Va · TR · Pa / TA / Pr where: TR is the reference temperature, in K (at 20 °C, TR = 293 K) TA is the ambient temperature, in K (TA = 273 + Ta) Pr is the normalised pressure, in bar (Pr = 1 bar) The result is VN = 0,0846 m3. The normalised rate of gas emission, GE at 2.4 V per cell, is given by:

GE = VN / 12 / C3 / 96 The result is GE = 9,06 ·10-8 m3, per Ah, per h, per cell.




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4.4. High current endurance Three SMG200S units were subjected to the high current endurance test. The units were identified with numbers 34-36.

4.4.1. High current test procedure

The units were initially subjected to a 3-hour rate discharge. They delivered a capacity Ca3 higher than the rated capacity. The units were then fully recharged. The three units were discharged for 1 minute at a constant current equal to 3.5 times the 5 minute current specified for an end of discharge voltage of 1,6 Vpc. In these conditions the discharge current is equal to 1260 A. Figure 6 shows the unit voltages during the discharge.

1,000

1,020

1,040

1,060

1,080

1,100

1,120

1,140

1,160

1,180

1,200

0 10 20 30 40 50 60 70 80

Seconds

Vo

lt

Unit 34

Unit 35

Unit 36

Figure 6, Discharge at 1260 A for 1 minute




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4.4.2. High current test result

During the test the units did not show indication of combustion and did not explode as result of self-ignition. After the discharge the units delivered a capacity Ca3 higher than the rated capacity. The discharge data is reported in Appendix I. Table 30 shows the capacity delivered before and after the high current endurance test.

Initial capacity at 3 h rate

(% of rated)

Capacity after the test at 3 h

(% of rated)

Unit 34 118 112 Unit 35 121 116 Unit 36 124 119

Table 30 Percentage of capacity before and after the high current endurance test

The requirements for passing the test were satisfied.




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Appendix A: Charging procedure Unless otherwise specified, the batteries charging procedure at 20°C was the following: The units were subjected to a constant voltage Uc = n · 2.40 were n is the number of the cells connected in series. The maximum charging current was fixed to 0.25 · C10 ampere, were C10 is the rated capacity in 10 hours. The constant voltage value has to be modified accordingly to the temperature as reported in the following equation:

Uc (T) = Uc (20°C) – 0.0025 · (T –20°C) where T is the actual temperature. The surface temperature immediately prior to the discharge test must be between 10°C and 35°C.

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Characterisation of FIAMM SMG Solar PRODUCT …batteryaustralia.com.au/wp-content/uploads/2014/12/Fiamm... · Industrial Batteries Characterisation of FIAMM SMG Solar product range