Level 1

Think of a jug

• You can pour water into it and pour water out of it.

• It doesn't make water.

• It doesn't use water.

• It is a place to store water; you can pick it up and move around.

Now, swap water for energy, and your jug becomes a rechargeable battery.

• It doesn't produce energy.

• It doesn't use energy.

• It stores energy so that you can pick it up move it about and use it later.

Level 2

Scientifically speaking you can't "make" energy. If you want energy you have to convert something that already has energy into a form of energy you can use.

In a battery, the energy is normally in the form of chemicals. When you use the battery some of the chemicals inside travel from one side of the battery to the other. These chemicals are typically positive or negative. If the positive chemicals move to one end of the battery this makes that end positively charged. You now have two poles (like a magnet) one positive and one negative. Electrons (the particles that move electricity) are negatively charged. If you connect a battery to a circuit, the electrons in the circuit will be attracted to the positive end of the battery (opposites attract). Electricity is just the flow of electrons. So a battery is a way of converting energy stored in chemicals into a flow of electricity.

Level 3

"An electrochemical energy storage device that directly converts chemical energy stored in the materials within into electrical energy."

This is a scientific definition specifically for a bog standard AA-type battery. But there are many different types of "battery" outside of the standard ones most people are familiar with.