Electricity-producing cells which use interaction of metals and chemical to create electrical current flow.
An electrical battery is a combination of two or more electrochemical cells used to convert stored chemical energy into electrical energy.
There are two types of batteries: primary batteries (disposable batteries), which are designed to be used once and discarded when they are exhausted, and secondary batteries (rechargeable batteries), which are designed to be recharged and used multiple times. (Wikipedia)
In common usage, the word "battery" has come to include a single galvanic cell, but a battery properly consists of multiple cells.
Charge and Discharge Cycle (click to enlarge)
Laws of Electrolysis
What Electricity Is - Bloomfield Moore
zinc copper iron electrochemistry