Potato Battery
Grade Level: 6
Strand: Understanding Matter and Energy
Topic: Electricity and Electrical Devices
Lesson Expectation: Design, build, and test a device that produces electricity
(e.g., a battery built from a lemon or potato; a wind turbine)
Required Materials:
- 3 potatoes
- 4-6 pennies (copper pennies)
- 4-6 galvanized nails (or zinc nails)
- 8 alligator clips
- Copper wires
- Low-voltage calculator or low-voltage light bulb
Procedure:
1. Insert a galvanized nail into each potato
2. Insert a penny into each potato. Be sure to keep the penny away from the
nail (not touching)
3. Wrap the ends of a copper wire around an alligator clip (2 alligator clips
per one piece of copper wire). Do this until all the alligator clips are
connected to copper wire.
4. Connect an alligator clip to a galvanized nail in potato 1; attach the other
alligator clip to a penny in potato 2. Then connect the alligator clip to the
galvanized nail in potato 2 and attach the other end of the alligator clip to
the penny in potato 3.
5. All the potatoes are connected by wires. Connect an alligator clip to the
galvanized nail in potato 3 and connect the other end to the negative end
of the calculator.
6. Attach the last set of alligator clips to the nail in potato 1 and to the
positive end of the calculator
7. With the circuit complete the calculator should turn on
Scientific Explanation:
A potato contains chemical energy. An electrochemical cell converts chemical
energy into electrical energy. A type of electrochemical cell is the potato battery.
This is due to the transfer of electrons between the zinc nail and copper penny.
The potato transfers the electrons (conducts electricity), but keeps the zinc ions
and copper ions separate. This separation forces the electrons to transfer over
the copper wires (generate current). This then channels the energy into the clock.
If the zinc ion and copper ions touched they would react but would only generate
heat. The potato battery does not contain enough power to shock a person, but
can power small electronics.
Other considerations: Other foods can also act as an electrochemical cell. Try
using citrus fruits, pickles, or cola.
Definitions:
 Electricity – energy created by moving charged particles (such as
electrons, positrons, and ions)
 Electrons – elementary particle; a stable negatively charged elementary
particle with a fundamental constituent of matter and orbits the nucleus of
an atom
 Chemical energy – the energy released or absorbed during the
decomposition or formation of compounds
 Electrical energy - is the presence and flow of an electric charge
 Electrochemical cell - is a device capable of either deriving electrical
energy from chemical reactions
Sources:
http://www.kidzworld.com/article/4726-how-potato-batteries-work
http://chemistry.about.com/od/chemistryhowtoguide/a/fruitbattery.htm
http://www.youtube.com/watch?v=AY9qcDCFeVI
http://www.youtube.com/watch?v=ufoOJfzro2c
By: George Franko & Meagan Warnock