Battery is widely used, can be used for ups, electric cars, scooters, cars, wind energy solar systems, security, and so on.
It filled with lead plate filled with sponge lead as a negative electrode, filled with lead dioxide lead dioxide as a positive electrode, and with 22 to 28% dilute sulfuric acid as electrolyte. In the charge, the electrical energy into chemical energy, the discharge of chemical energy and into electrical energy.
Battery is a kind of battery, its role is to be able to save the limited power, in the right place to make 6v4ah emergency light battery. Its working principle is to convert chemical energy into electricity.