The charging system and starting system are designed to have a very long life in modern vehicles. Often a failure in either system is caused by an outside influence. For instance, the belt that drives the alternator is rubber and can wear out and stretch. If the belt tension is not set correctly, the belt will not drive the alternator properly and may prevent the battery from receiving the charge it needs to operate the starter motor from a cold start.
What can go wrong
Extreme temperatures can accelerate battery wear and shorten the life of the battery. So, in extremely cold or hot climates, it is a good idea to get your battery tested every year.
Also, leaving lights on or running the radio for a long time after you turn off the engine can leave the battery without enough charge to operate the starter motor. With DVD players and GPS units in many cars, it is easier than ever to run down the battery after you turn the car off. Be aware of electrical usage and make sure to turn off additional features while the battery still has plenty of charge left.
Care and maintenance
Manufacturers recommend routine inspection of the starting and charging system every 100,000 miles.
The battery should be checked at least once per year because it requires maintenance and care. Some types of batteries require the water to be checked during the yearly maintenance cycle and the positive and negative terminals should always be kept free from corrosion. Corrosion could cause problems with the electrical circuit and keep the battery from delivering the full charge to the starter motor.