Fruit-Power Battery

Convert chemical energy from the acid in a lemon into electrical energy

Voltaic batteries of all shapes and sizes are objects that convert chemical energy into electrical energy. You probably use batteries to power your cell phone, iPod, or any number of wireless gadgets. But did you know that you can actually use chemical energy stored within a lemon to power a small LED light? It's true, and we'll show you exactly how in the Fruit-Power Battery experiment.


  • Four lemons (the bigger and juicier the better)
  • Four pennies
  • Five zinc-galvanized nails
  • Five sets of alligator clips
  • LED light
  • Kitchen knife


  1. Use a kitchen knife to cut a penny-sized slit in all four lemons.
  2. Insert a penny halfway into each of the four slits that you cut.
  3. Push a zinc-galvanized nail into each of the lemons, opposite the penny. Be sure you don’t let the nail and penny touch each other.
  4. Connect all four lemons together with alligator clips. Each set of alligator clips should connect a nail with a penny.
  5. Attach the two loose alligator clips to the LED light.
  6. Check that out! The energy from the lemons lights up the LED.

How Does It Work?

Batteries are comprised of two different metals suspended in an acidic solution. With the Fruit-Power Battery, the two metals are zinc and copper. The zinc is in the galvanization of the nail, and the penny is actually copper-plated zinc. The acid comes from the citric acid inside the lemon.
The two metal components are electrodes, the parts of a battery where electrical current enters and leaves the battery. With a zinc and copper set-up, the current will flow out of the penny and into the nail. The electricity also passes through the acidic solution inside the lemon.
Once the Fruit-Power Battery is connected to the LED, you create a complete circuit. As the electrical current passes through the LED, it lights the LED, and passes back through all of the lemons.