By Chelsea Oliver | Updated Mar 24, 2022

Citrus fruits—such as oranges, lemons, and grapefruits—contain citric acid, which reacts with metal electrodes to produce a measurable electric current. When paired with copper and zinc, an orange can serve as a simple battery capable of lighting an LED or powering a basic digital clock. This hands‑on experiment offers students a clear illustration of electrochemical principles and the role of acids in battery chemistry.

Step 1

Gently squeeze the sides of the orange to loosen its juice, preparing the fruit for the experiment.

Step 2

Insert a copper nail and a galvanized zinc nail into the orange. Position the nails so that their tips are centered inside the fruit and about 2 inches apart.

Step 3

Take a small LED or other low‑voltage light bulb. Strip approximately 2 inches of insulation from each lead, exposing the bare wires.

Step 4

Wrap one exposed wire around the zinc nail and secure it with electrical tape if needed. Repeat with the other wire, attaching it to the copper nail.

Step 5

Once both wires are connected, the orange generates enough voltage to light the LED, demonstrating a working fruit‑based battery.

Materials Needed

• 1 orange
• 1 copper nail (2 inches long)
• 1 galvanized zinc nail (2 inches long)
• 1 small LED or low‑voltage light bulb with 2‑inch leads
• Electrical tape (optional)
• Micro ammeter (optional, for measuring output)
• Crocodile clips (optional, for easier connections)

TL;DR (Too Long; Didn’t Read)

Attach a micro ammeter to the copper and zinc nails using crocodile clips to measure the orange’s voltage output. Then connect the LED to see the fruit battery in action.