Types of batteries
There are two general classifications of batteries: disposable and rechargeable.
Disposable batteries are also called primary batteries. They are designed so as to store chemical energy and then convert this to electrical energy irreversibly. Once the chemicals run out, the battery cannot be used again.
Rechargeable batteries, on the other hand, are designed so as to be able to reverse the chemical reactions that convert the energy into different forms. When the reactants are gone, they can be reversed to the initial form to be reconverted to electricity once again.