How to Make a Lemon Battery for a 3rd Grade Science Project

Lemon juice can conduct electricity.

Electricity is generated by the movement of electrons. A voltaic battery creates electrical energy using electrodes and a chemical solution called an electrolyte, which contains positive or negative atoms called ions. The ions in the electrolyte solution react with the metal electrodes. Electrolyte solutions, such as vinegar, salt water or lemon juice, conduct the electrons from one electrode to another to create electricity. A lemon battery experiment can be easily set up for a third-grade science project.

Things You'll Need

• Lemon
• 2-inch-long galvanized nail
• 2-inch-long copper wire
• Voltmeter

Instructions

1. Select a large, fresh lemon to serve as the battery. Roll the lemon on a table while pressing down on it, not breaking the skin, to crush the pulp so that the juice is released inside the lemon.

2. Insert the 2-inch-long galvanized nail into one side of the lemon, leaving about an inch protruding from the lemon. Insert the copper wire into the other side of the lemon, leaving an inch of wire protruding.

3. Connect the voltmeter to the lemon battery by attaching one clip to the nail and the other clip to the copper wire. Note the amount of current that is passing from one electrode to the other.

Tips & Warnings

• Use other objects to make a voltaic battery, such as a potato, an orange, a lime or a glass of salt water. Compare the strengths of the electrical charges created by the various batteries.

• Increase the strength of the lemon voltaic battery by connecting lemon batteries in a series.

• Third-grade students can draw a large poster diagram of the battery to show how electrons flow from one electrode to another.

• An adult should supervise the construction of the lemon battery. Copper wire and nails are sharp and can cause injury.

References

• Energyquest.ca.gov: Lemon Power
• Hila Science Camp: Lemon Battery

Resources

• Science Buddies: A Battery That Makes Cents