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/howbatt
erieswork.asp