S ScienceFairProjects.info
Easy⏱ time25 min$ cost6

Lemon Battery Array

Wire lemons with zinc and copper electrodes in series to light a real LED from fruit.

Start building ↓
fig — working model Result first

The build

Step 01

Prep the cells

Roll lemons, then insert one zinc nail and one copper coin into each (not touching).

Step 02

Wire in series

Clip copper of one lemon to zinc of the next, chaining all four.

Step 03

Attach the LED

Connect free copper to the LED's long leg, free zinc to the short.

Step 04

Dim the room

A faint glow appears; add a lemon if needed.

Working Principle

Each lemon is a galvanic cell: zinc gives up electrons while copper hosts reduction, and the acidic juice carries ions to complete the circuit.

The science behind it

A closer look

One cell makes ~0.9 V; wiring cells in series adds their voltages until the LED's turn-on threshold is reached.

Take it further

Variables to test

  • 1 Compare lemons, potatoes and vinegar — which gives most voltage?
  • 2 Measure voltage with 1–4 cells — is it linear?

More Chemistry