1. 12 December, 2010
2.10 Producing electrical
energies: batteries

4. DC versus AC
• A direct current (DC) is one which goes
around and around in the same direction –
it is delivered from a battery
• An alternating current (AC) is one which
goes back and forth over and over again –
this is what we get from the mains supply

5. • If you look at a
battery you will see
two terminals
• One is a +ve called
the anode
• The other is –ve
called cathode

7. Examples of different types of batteries
and where we use them
Appliance Battery material Battery type
Mobile phone Lithium ion Rechargeable
Modern car Lithium acid Rechargeable
Very old car Lead acid Rechargeable
Laptop Lithium ion Rechargeable
Television remote control Alkaline Non-Rechargeable
Watch Lithium iodide Non-Rechargeable

8. Non-rechargeable batteries
• A battery is made of a number of cells
• AAA is a 1.5 V cell, a PP3 is a nine volt
battery

9. The dry cell

10. How do they work?
• When the two poles are connected the electrons
can flow
• As the chemicals are used up fewer electrons
are made so the battery is used up
• A chemical reaction occurs between the
electrolyte and the anode which produces
electrons
• The salt bridge is in the way so they cannot flow
• These electrons flow to the cathode where there
are few electrons but…

11. How do they work?
1. A chemical reaction occurs between the
electrolyte and the anode which produces
electrons
2. These electrons flow to the cathode where
there are few electrons but
3. The salt bridge is in the way so they cannot
flow
4. When the two poles are connected the
electrons can flow
5. As the chemicals are used up fewer electrons
are made so the battery is used up

12. Why do we use them?
• Little current (like
remote controls)
• Rarely used items
(torches)
• They are cheap
• Stay charged for
longer
• …bad for the
environment!

13. Rechargeable batteries
• Cells in rechargeable batteries are called
secondary cells
• These are mostly used in portable items
that are used regularly, such as mobile
phones and computers
• The chemical is used up as the battery is
used but the process is reversible by
applying an electrical current

14. Safety hazards
• Dead batteries must be disposed of safely
• Some batteries contain toxic mercury that
may leak into the environment
• Leaking batteries may also cause burns if
the acid comes into contact with the skin
• In some areas of the UK, all types of
battery can be recycled

15. Questions
• Explain the difference between a
rechargeable and a non-rechargeable
battery. Give five examples of each
• Draw a labelled diagram of a primary cell
• Discuss with a partner the advantages and
disadvantages of rechargeable and non-
rechargeable batteries