A battery, or battery, is a device that converts chemical or physical energy into electrical energy through a reaction. Batteries can be divided into chemical batteries and physical batteries according to the difference of energy converted by batteries.

A chemical battery or a chemical power supply is a device that converts chemical energy into electrical energy. It consists of two electrochemically active electrodes of different components, respectively composed of a positive and a negative electrode, a chemical that provides media conduction as an electrolyte, when connected to an external carrier, by converting its internal chemical energy to provide electrical energy.

A physical battery is a device that converts physical energy into electricity.