Making a potato clock is a fun science experiment. You don't have to use conventional electricity or batteries to power everything; power can come from unusual places. To make a potato clock, you can use supplies lying around the house; if not, everything can be found at the local hardware and grocery stores.
- 2 large potatoes
- 2 galvanized nails
- 2 copper nails or 2 pieces of heavy copper wire
- Small battery operated LCD clock, 1.5V-2V
- 3 jumper wires with alligator clips on each end
Insert galvanized nails. Place one galvanized nail into each potato. Make sure that they are galvanized; the zinc coating is what allows the potato to work as a battery. Do not push them in all the way; leave some part of each nail sticking out of the potato.
Insert copper nails or wires. Then place one copper nail into each potato, making sure that the copper and galvanized nails do not touch. If they do touch, your circuit will not work. For best results, the copper nail or wire should be as far away from the galvanized nail as possible. Again, do not push them all of the way into the potato.
Remove battery from clock. Remove the battery from the LCD clock. Pay attention to how the batteries' polarity relates to the clock, because you'll need to know where the positive and negative ends of the battery were situated inside the clock. Your potatoes will replace this battery to run the clock.
Connect the wires. Using the first jumper wire, connect the copper nail of the first potato to the positive terminal of the clock (where the battery used to be). Then connect the second wire from the galvanized nail of the second potato to the negative terminal of the clock, which was the other side of the battery.
Complete the circuit. Connect the third jumper wire so that it leads from the galvanized nail of the first potato to the copper nail of the second potato.
Set the clock. The clock is now running on potato power.
A potato clock runs on a potato instead of a conventional battery. A potato "battery" is a type of electrochemical cell. In the potato, electrons are transferred between the galvanized nail and the copper nail, conducting electricity. This is a low-power homemade battery; it will not give you an electric shock, but it can run a low-power clock.