Car batteries cannot recharge themselves without first receiving power from an outside source. A common method of providing the initial power to start a dead battery is through connecting the dead battery to a live one in another vehicle with jumper cables.
There are several brands of home battery chargers that can be used to maintain power. All batteries gradually break down over time through acid buildup, which is visible as a white powdery substance on the battery's terminals. Battery life can be affected by climate, how often the car is driven and the frequency of car and battery maintenance.