The NASA SCIence Files™
Homemade Batteries - Grades 4 & 5
Purpose: This activity shows you how to build and test a simple homemade battery to better understand electricity.

Materials

Procedure
  1. Roll the lemon a few times on a counter to get the juices flowing.
  2. With adult supervision: Use the knife to make two parallel (side by side) slits 2 cm apart in the lemon.
  3. Make a small nail hole in the end of the metal copper and zinc strips.
  4. Insert the copper strip into one slit and the zinc strip into the other slit so that they stay 2 cm apart.
  5. Connect the wire leads to the copper strip and the zinc strip by looping the wires through the holes made by the nail.
  6. Connect one of the ends of the wire to the terminals on a lamp (bulb holder) or on one end of the galvanometer.
  7. Predict what will happen when the loose wire touches the lamp terminal or the galvanometer.
  8. Take the other loose wire end and touch it to the open terminal of the lamp or galvanometer to complete the circuit in short intervals.
    • The current is too weak to electrocute anyone!
    • If the galvanometer is used as the load, record the reading.
    • If the lamp with a bulb in it is used, note the brightness of the bulb.
Conclusion
  1. What is the power source?
  2. Would two strips of the same metal produce electricity?
  3. What other fruit can be used instead of the lemon?
  4. List the circuit parts.

Answer Key

1. What is the power source?

The acid in the lemon is the power source.

2. Would two strips of the same metal produce electricity?

Strips of the same metal would not produce electricity.

3. What other fruit can be used instead of the lemon?

An orange or a grapefruit can also be used in this experiment.

4. List the circuit parts.

The parts of the circuit include acidity in the lemon (power source); copper and zinc metal strips (conductors); wires (carry the electricity); lamp bulb holder and/or galvanometer (load); loose wire end (switch).