Why do I need a battery?

Chapter 7 Section 2

What does a battery do?

• Static discharge is the moving of electrons from one atom to another.

• In order to keep the electrons moving through the circuit, there has to be something that causes a push, or a voltage difference- a battery does just that…

How do batteries work?

• Batteries create an uneven level of electrons which causes the electrons to move from a high concentration to a low concentration…

• This is also known as the voltage difference..

Dry-Cell Batteries

• Where do you find these?

• Name at least three places you use these…

Dry Cell Batteries

• There are two main parts on a battery that creates the voltage difference…

• The positive and negative ends…• Do you know which is which ?

Parts of the Dry Cell

• Positive End • Plastic Insulator • Moist Paste • Carbon Rod • Zinc Container • Negative Terminal

How does a Dry Cell Work?

• When the circuit is closed, and the battery is connected, a chemical reaction starts the process.

• The chemical reaction with zinc and several other chemicals occurs in the moist paste.

How does a Dry Cell Work?

• The carbon rod acts as a conductor and transfers electrons.

• The carbon rod is not part of the reaction happening in the moist paste.

• But…the chemical reaction in the moist paste does cause the carbon rod to become charged.

• This charge on the carbon rod creates a positive end.

• The negative end is made by the Zinc.

How does a Dry Cell Work?

• The voltage difference between the positive and negative ends causes the current to flow.

• By connecting more batteries you increase the voltage difference.

• List three things that needs more than one battery to work…

Wet Cell Batteries…

• What is a wet cell battery?• A battery that contains two

connected plates made of different metals or metallic compounds in a conducting solution.

• Can you list three places you have seen or used a wet cell battery?

Parts of a Wet Cell Battery

• Positive end• Negative end• Lead Plate• Battery Solution• Partition• Lead dioxide plate

THE BATTERY WEBSITE

• http://www.energizer.com/learning/howbatterieswork.asp