E-lemon-tricity

You can actually build your own battery with some items you may have around the house, starting with, of all things, a lemon!

What you'll need:

1 lemon

Small knife

Voltmeter

Metals for electrodes:

New, shiny penny (copper)

Steel paper clip (mostly iron)

Aluminum foil (1/2" x 1")
Galvanized nail (zinc-coated)

Roll the lemon on a table or other surface. Cut a slit in the wide middle part of the lemon to the penny, paper clip, or aluminum foil electrode. The nail can be just pushed in. Place two electrodes in the lemon about one inch apart. Touch one lead from the voltmeter to one electrode; touch the other lead to the second electrode. Read the voltage. Change one of the electrodes and measure the voltage again. Check these combinations: penny-paper clip; penny-foil; penny-nail; paper clip-foil; paper clip-nail; foil-nail. Are the voltages the same or different?

You'll find that the voltage changes depending on the metals used. The largest voltage probably came from the penny-nail (copper-zinc) combination. Now, the voltage coming from this battery isn't very high, and it can't be used to power any devices like a flashlight, calculator, or iPod. You can actually connect a couple of lemon batteries together to light up an LED (small lightbulb), but this requires some additional equipment. If you are interested in trying this, check out this video.