Food Batteries

This article shows you how to make a battery from vegetables or fruits.

In the early 1990s, I saw a science show on TV where kids connected about 20 lemons with electrodes to power a light bulb.

I purchased a Potato Clock Kit from Jaycar Electronics. It was just another digital clock except that this kit had two electrodes that you connect to a potato instead of a battery holder. One electrode was made from copper and electrode was made from zinc. The clock was not working properly. Probably the clock needed more power.

You can watch the 37-second video or read the whole article.

You will need food with lots of energy such as potato or lemon. You can experiment with different fruits and vegetables. You will also need a copper electrode and a zinc electrode. Another important component is the voltmeter so that you can measure the presence of the voltage.

You can see in the videos that you can connect the electrodes almost anywhere and still get power from the vegetable and fruit.

The red potato gave a 1.5 V output, the yellow potato gave a 1 V output and the lemon gave also a 1 V output.

The voltmeter input resistance was only 12,000 ohms. Not very high for a voltmeter. This low input resistance could have reduced the measured voltage. It is important the mention that food battery like any other battery would have internal resistance that would affect the output voltage.

You can try connecting multiple potatoes or lemons in a series to get larger voltages.