How to Make a Lemon Battery for a Science Project

Lemon juice acts as electrolyte fluid producing chemical reactions that emit electricity.

Most people's concept of a battery does not typically include fruit, but in fact, you can transform lemons into a little power plant to make a lemon battery for a science project. The voltage output of your lemon battery will run a small load such as a digital clock or a holiday light bulb. Practice connecting the circuit and attaching the load at home before setting up a demonstration in class or at the science fair.

Things You'll Need

• 2 lemons
• 2 galvanized nails, 3 inches long
• 5 feet copper wire, 24 gauge
• 6 inches 12 gauge copper wire
• 5 jumper leads with alligator clips
• 2 large paper clips
• 2 pennies
• Multimeter
• Wire cutters
• Optional:
• Resistors
• battery-operated timer, calculator, 3-volt radio, holiday lightbulb or small digital clock

Instructions

1. Squeeze the lemons slightly and roll on table to loosen the pulp, recommends PBS' Zoom Sci.

2. Cut three 12-inch lengths of 24-gauge copper wire. You will need two types of electrodes. Use pennies or 12-gauge copper wire for the copper set and paperclips or galvanized (zinc-coated) nails for the second. Wrap one end of the first piece of 24-gauge wire (wire C) around a penny or a 3-inch length of 12-gauge copper wire. Wrap the other end around a nail or paperclip. Insert the nail or paperclip into one lemon (lemon 1) and the copper penny or wire in the other (lemon 2).

3. Wrap the end of the second 24-gauge wire around a penny or another 3-inch piece of 12-gauge copper wire several times (wire A) and the third wire around another nail or paperclip (wire B). Insert the copper post or penny on wire A into lemon 1, leaving an inch between the two electrodes. Insert nail or paperclip on wire B into lemon with the same spacing.

4. Hook the free end of the wire A to the multimeter's positive terminal and wire B to the negative terminal. Read the voltage output of your lemon battery.

5. Wrap the end of another piece of 24-gauge copper wire around the nail or paperclip and the penny or copper post that connects to the multimeter. Attach the free ends to the terminals of a load such as a resistor, battery-operated timer, calculator, 3-volt radio, holiday lightbulb or small digital clock, suggests Science Buddies.

Tips & Warnings

• In lieu of the copper wire connections, you can use jumper leads with alligator clips.

References

• PBS Kids: ZoomSci -- Lemon Battery
• Science Buddies: Veggie Power! Making Batteries from Fruits and Vegetables