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How to Make a Lime Clock

A battery needs three elements to produce an electric current: a positive electrode, a negative electrode and a conductive solution called an electrolyte, which allows electrons to flow from one electrode to the other. In a lime battery, a copper strip is the positive electrode, or cathode; a zinc-coated galvanized nail is the negative electrode, or anode; and lime juice serves as the electrolyte. Although a lime battery doesn't provide much current, it should be able to power a small LCD clock.

Things You'll Need

2 limes
2 galvanized nails, 2-inch
Sandpaper
2 copper strips, 2 inches long by 1/4-inch wide
3 insulated copper wires with alligator clips
1.5-volt LCD clock

Instructions

- 1
  Roll each lime firmly against a table -- or between your palms -- to make the juice inside flow.
- 2
  Insert a galvanized nail halfway into each lime. Clean the copper strips with a small piece of sandpaper. Insert a copper strip halfway into each lime, no more than an inch from the galvanized nail. Don̵7;t allow the metals to touch inside the limes.
- 3
  Connect the galvanized nail in one lime to the copper strip in the other.
- 4
  Clip one end of a wire to the free copper strip in one lime. Clip one end of the other wire to the free galvanized nail in the other lime.
- 5
  Remove the battery from the LCD clock, if necessary. Attach the wire from the copper strip to the clock̵7;s positive (+) terminal. Attach the wire from the galvanized nail to the negative (-) terminal. The clock display should light up within a few seconds.

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