How Batteries Work

Batteries are portable power sources that run all kinds of devices. They power flashlights, toys, phones, and cars. Inside a battery, chemical reactions produce electricity. When the chemicals are used up, the battery dies. Rechargeable batteries can be refilled with energy.

Inside a Battery

A battery has three main parts: two electrodes and a chemical paste called an electrolyte between them. One electrode is positive and the other is negative. A chemical reaction at the negative end releases electrons. The electrons want to flow to the positive end. When you connect the battery to a device, electrons flow through the device and power it.

Rechargeable Batteries

In a regular battery, the chemical reaction can only go one way. Once the chemicals are used up, the battery is dead. In a rechargeable battery, electricity from a charger reverses the chemical reaction. This restores the chemicals to their original state. The battery can then produce electricity again.

Fun Facts

• The first battery was invented in 1800 by an Italian scientist named Alessandro Volta.
• A lemon can be turned into a simple battery using a copper coin and a zinc nail.
• The battery in an electric car can contain about 7,000 individual battery cells.

Did You Know?

An ancient object called the Baghdad Battery was found in Iraq. It is a clay jar with a copper tube and iron rod inside, dating back about 2,000 years. Some scientists think it might have been an early battery!