Voltage      Chemical      Cranking Power

When you place the key in your car's ignition and turn the ignition switch to "ON," a signal is sent to the car's battery. Upon receiving this signal, the car battery takes energy that it has been storing in chemical form and releases it as electricity. This electrical power is used to crank the engine. The battery also releases energy to power the car's lights and other accessories.

How a Battery Works | How to Jumpstart a Battery | Definitions
Safety and Handling | Maintenance & Storage Tips | Charging a battery
Selecting the Right Battery | Recycling