The starting and charging system makes sure you can start your car and use all of the features that need electricity to operate.
The Starting System
The starting system is made up of the starter motor and the ignition switch. The starter motor is a high-torque electric motor that literally turns the engine until the cylinders can combust fuel, starting a chain reaction that keeps the engine running. The starter motor draws its power from the battery. It requires quite a bit of power, so if your battery is running low, your car may not start.
The Charging System
The charging system is made up of the battery and alternator. The alternator is connected to the engine by a belt that spins the alternator to generate electricity like a generator. This electricity recharges the battery and provides the power needed to run all of the electrical components in the car. The battery stores electricity for later use to operate the starter motor.
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.