Operation CHARM: Car repair manuals for everyone.

Common Causes of Battery Failure

The battery is not designed to last indefinitely; however, with proper care, it will provide many years of service.

When the battery tests OK, but for no apparent reason fails to perform satisfactorily in service, the following are some important factors that may point to the problem:

1. Vehicle accessories left on overnight.
2. Operating vehicle for an extended time at slow speeds for short driving distances.
3. The vehicle's electrical load is more than the generator output, particularly with the addition of aftermarket equipment.
4. Conditions in the charging system, such as electrical shorts, poor ground circuits, or a slipping generator drive belt.
5. Battery abuse, including dirty and/or loose battery cable terminals, or a loose battery hold-down.
6. Mechanical problems in the electrical system, such as shorted or pinched wires.