Potato Clock

What Is A Potato Clock?

A potato clock runs by converting chemical engineer to electrical energy which is later used as a clock. By using zinc and copper strips, the potato can be used as a battery. Zinc strip is used because it starts to dissolve when it reacts with mild phosphoric acid in the potato as there is a release of electrons resulting in electrical power.

How to make a Potato Clock?

Potato Clock

Do you know that the potatoes are a great conductor of electricity? Now you can build a clock that does not require any kind of batteries to run on, but simply regular potatoes. Learn how to make a clock with the help of just a potato.

Materials required:

In order to power a clock with potatoes, you will need the following materials:

  • Two large potatoes.
  • A marker pen.
  • A pair of scissors or a wire cutter.
  • Two galvanized nails.
  • Copper wire.
  • Three jumper wires with alligator clips.
  • A digital LED clock that uses one AAA or AA battery.

You can easily find galvanized nails, copper wire, and jumper wires at all hardware stores.


  • Using the marker, label the potatoes “A” and “B”.With the help of an adult, cut two pieces of copper wire using scissors or a wire cutter. These pieces should be about 5 centimeters long.
  • Open the battery compartment of the clock and remove the battery inside.
  • Insert a galvanized nail into each potato. Only insert half of the nail.
  • Repeat the previous step with the copper wire. Keep the nail and the copper wire as far away as possible from each other. Make sure they do not touch each other inside the potato.
  • Connect the copper wire of potato“A” to the positive terminal of the clock’s battery compartment using the first jumper wire. The positive terminal is usually labeled by the symbol “+”.
  • Connect the galvanized nail of potato “B” to the negative terminal of the clock’s battery compartment using the second jumper wire. The negative terminal is usually labeled by the symbol “-”.
  • Connect the galvanized nail of potato “A” to the copper wire of potato “B” using the third jumper wire.
  • Take a look at the screen of the clock. Can you see that the clock has now turned on?

What did you learn?

In this project, the potatoes create an electrochemical cell, which converts chemical energy into electrical energy. The galvanized nail is coated in zinc, an element that chemically reacts with the copper in the wire. This reaction is known as electron transfer. The potatoes both conduct electricity and keep the zinc and the copper apart from each another, allowing an electric circuit to be created. The movement of electrons generates electrical power for the clock.

Stay tuned with BYJU’S to learn more other Physics related concepts.

Practise This Question

In Galileo's experiment in order to reach the same height how far must the ball go on the horizontal surface after being released from an incline of a height of 5m?