What is a battery?

A battery is made up of a collection of cells. A battery is a store of chemical energy. When the energy is released from a battery, it 'flows' as electrical energy. It takes more energy to start a motor car engine than it takes to light the bulb in a torch. Therefore, a car battery is much bigger than a torch battery.

How is energy stored in a battery?

A battery contains chemicals which contain energy. If chemicals are brought into contact with each other in certain ways, energy 'flows' from one chemical to the other. So, a chemical reaction produces chemical energy.

This, roughly, is how a battery works. The 'flow' of energy is in fact caused by millions and millions of tiny particles, called electrons, moving along a wire. The electrons ‘flow' (move) along the wire from one substance to the other. This movement of electrons is called an electric current.

Although a battery stores energy as chemicals, when the energy is released from the battery it travels in wires in the form of electrical energy.