Build a Potato Battery

  1. three potatoes
  2. galvanized nails (coated in zinc)
  3. copper coins
  4. copper wire
  5. alligator clips
  6. scissors, knife
  7. tiny LED, red require the least amount of energy


  1. Stick a nail into one end of each potato.
  2. Stick a copper coin into the other end of each. You can use a knife to cut a slit to squeeze in the coin.
  3. Cut the wire into four pieces, each about 6 inches (15 cm). Make sure it is copper wire. If it is covered with a plastic casing, please strip it away at the ends.
  4. One end of the wire gets wrapped the metal part of an alligator clip. Clip it to the coin.
  5. Arrange the potatoes in line. Wrap the loose ends of the wire around the nail in the next potato. Wrap the extra wire around the first nail.
  6. Connect the LED to the wires from the first nail and last coin, to complete the circuit. It should form a circle.


  1. The coin is like the plus side on a battery.
  2. The nail is the negative side.
  3. Make sure no wires are touching each other. That would redirect the flow of electrons, electricity.
  4. The LED should light up.
  5. If it doesn’t work, try a smaller LED if possible or make more three-potato batteries and connect the end wires from all of the coins together and then all of the end wires from the nails together and then use a wire from each of those bundles to connect to the LED.