While most new batteries last around five years, factors including climate, over or undercharging, etc. can impact on the life of a battery. In most cases, if a battery is over four or five years old, it should be replaced. Auto mechanics and service facilities will install batteries but it can be done by the car owner quickly and less expensively. The procedure itself is fairly simple if certain details and safety rules are followed.

First, make sure that the battery purchased is the one made to fit the particular type of car. The same type that is already in use may be adequate or another more powerful or expensive battery may be desired. However, do not exceed the voltage requirements for the car. Consult the automobile owner's manual for the specifications or get assistance from the personnel at a reputable auto parts store.

Make sure that proper safety measures are taken when installing a battery, since serious acid burns to eyes and hands are possible. Use safety glasses and plastic glove to protect eyes and hands. After installing the battery, discard the gloves.

Disconnect the negative battery cable, then the positive cable. Remove the metal clamp that holds the battery in the battery tray. If rust is found in the bottom of the tray, wash with plain water and let dry before installing the battery. After drying, put the new battery into the tray and attach the metal clamps to secure the battery. These metal clamps should also be checked for rust or corrosion.

Before re-attaching the battery cables, make sure that the insides of the cable connectors are free from rust or corrosion. If present, use a thick paste of household baking soda and water to scrub the insides of the cable ends. This same paste can be used to clean the metal battery clamp. A small wire brush for scrubbing off this corrosion may be obtained from an auto parts store. Then spray with WD-40. Spray cable ends with WD-40 once every six months to guard against corrosion.

Make sure that cable wires are not frayed to insure a safe connection. Re-attach positive and then negative cables to posts and tighten until firm but not overtight.

If, for some reason, the car does not start, seek the assistance of a mechanic since some other problem may be present.