Walter Lewin explains how an acid battery works

3-Second Blueprint (English)

1. Immersing copper and zinc electrodes in a sulfuric acid electrolyte creates a galvanic cell that converts chemical energy to electricity.
2. Connecting multiple electrochemical cells in series sums their individual potentials to reach the voltage needed to light a bulb.
3. Simple unseparated acid cells produce only brief current bursts before electrode polarization and surface reactions reduce output.