Cameron has made a voltaic cell, which is a simple battery, out of a potato. This project is for the 4th grade
science fair at Collins Elementary School, in Cupertino California, which will be held on May 4th, 2000.
Cameron's Potato Page is to share with others the details of how the potato battery is made, and why it works.
Key Points
The Scientific Method
Construction
Safety
Key terms
Why it works
Sources and references on the web
The Scientific Method
The origin of this project was to demonstrate the application of the scientific method in finding answers to questions
about the physical world around us. The scientific method has four steps:
Observe
Form a hypothesis
Make a prediction
Test the predictin with experiments
Construction
Construction of a potato battery is very simple, but it does require some tools and adult supervision.
Sandpaper, to remove any dirt or corrosion from the copper and zinc electrodes.
Zinc metal strips, about one by three inches, to use as electrods. Cameron used galvinized steel gutter hangers, as the galvinizing is actually zinc plating!
Copper strips, also about one by three inches.
A very low voltage light bulb to test for battery output (being optimistic here!)
Wire cutters and needle-nose pliers
A soldiering iron and soldier is optional, but makes for better electrical connections.
Wire.
A mulit-meter capable of measuring tenths of volts DC will be needed to test for output if the light bulb will not light.
Tin snips to cut the copper and zinc to size.
Don't forget to sand the surface (and sharp edges) of your copper and zinc strips. Unless the electrolyte can interact with the actual metal, your cell will not
produce electricity. Make sure the metal is clean of paint, grease, and corrosion.
Safety First!
Prevent avoidable accidents by using some common sense during your construction. An adult should supervise the construction.
Use care during soldering. The iron gets hot enough to cause serious burns. Hot solder can splash, and cause burns as well.
A mis-laid soldering iron can start a fire. The iron also stays hot long after being unplugged.
Fumes from soldering are not healthy. Solder in a well-ventilated area.
Cutting metal for your electrodes may require using tin snips. This tool can cause injury if mis-used. Be careful of sharp edges on cut metal.
Do not bring any of your wires metal compenents close to any other electrical source. While your battery produces less than a volt, other electricity can be dangerous.
Key Terms
These are some terms that are useful in understanding why a potato battery works.
Battery - A group of voltaic cells connected together.
Conductor - Supports the flow of electricity.
Copper - Metal that interact with ions, and can be used as an electrode.
Current - The movement of actual of electrons of electricity.
Electrochemical Changing of chemical energy into electrical energy.
Electrode - The parts of a cell where electric current enters or leaves.
Electrolyte - A solution that conducts electricity.
Ion - Atoms that have either gained or lost at least one electron each, and are no longer neutrally charged.
Multimeter - Device used to measure voltage and current.
Parallel - Side to side. Connecting cells in parallel adds up the current, while voltage stays the same.
Series - One after another. Connecting cells in series adds up the voltage, while current stays the same.
Volt - The unit of measurement of electromotive force, much like water pressure.
Voltage - Measurement of electromotive force.
Voltaic Cell The basic part of a battery that produces electricity by electrochemical reaction.
Zinc - Metal that interacts with ions, and can be used as an electrode.
References and sources on the web
Learn more about the potato, and other food batteries, at these pages on the web...
