- A lemon battery requires an acidic fruit (lemon), a penny, a piece of zinc or a steel paper clip, two wires and a voltage meter. Two slits in the lemon hold the penny and and piece of zinc, each wrapped in their own wire. The ends of these wires connect to a multimeter to measure the volts and amps produced by the lemon battery. Some experiments connect several lemons together then wire them to a digital clock.
- Acid from the lemon reacts with the two metals. Copper and steel (or zinc) act as electrodes in the acid from the lemon. The different metals allow for atoms from one to move through the lemon to the other metal. This atomic movement cannot continue indefinitely and once it stops, the battery dies. As the atoms move, they lose electrons, which flow through the wires, producing electricity.
- Electricity requires a flow of electrons. Lemon batteries use chemical reactions to generate this electron flow. This conversion of chemical to electrical energy makes the lemon battery a voltaic battery. Voltage generated from a single lemon typically only registers 0.7 volts and to power a digital clock or watch requires at least two lemon batteries wired together.
