The car battery is the core of your vehicle's electrical system. The battery provides power for your engine to start and all the electrical systems of your car including lights, radios, and air conditioners. The alternator generates electrical energy while the engine runs. This stored energy is used to power the starter motor, ignition system and other electrical devices during start-up. During start-up, this stored energy is used to power the starter motor, ignition and other electrical components. The battery can also provide power if the electrical load of the car exceeds the amount supplied by the charging system. Maintaining a healthy battery for your car is essential to its smooth operation.