Potato Clock

Any free-standing device or an instrument that can display or measure the current time is known as a clock. A clock can be anything that can repeat itself predictably. One of the good examples of something repeating predictably is the rotation of the earth around the sun. It was the first method that mankind adopted to predict the time of the day. The technological and engineering challenges faced in building a clock are relatively complex and in the last two millennia has revolved around building an accurate, reliable timekeeping device. In this article, we will show you how to make your own timekeeping potato clock using simple steps.

What Is A Potato Clock?

A potato clock is a clock that is run by converting chemical energy into electrical energy which is later used to power a clock. Zinc and copper strips in combination with 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 electric power. In the battery, zinc serves as an anode and copper as a cathode.

How to make a Potato Clock?

Potato Clock

Did 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 the 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 other, 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.

Watch the video and understand Indian Standard Time.

Frequently Asked Questions – FAQs


Define clock.

It is a device or an instrument that can display or measure the current time.

State true or false: Electrical energy is converted into chemical energy in a potato clock.

False. In a potato clock, chemical energy into electrical energy.

Do potatoes conduct electricity?

Yes, potatoes are a great conductor of electricity.

What is meant by time?

Time can be defined as the dimension based on which the evolution of any system takes place.

In a potato clock, which metal serves as an anode?

Zinc serves as an anode in a potato clock.
Test Your Knowledge On How To Make A Potato Clock!


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