What is the primary function of an alternator in a vehicle?

The primary function of an alternator in a vehicle is to recharge the battery. When the engine is running, the alternator produces electrical energy to keep the battery charged and to power the vehicle's electrical systems, such as the lights, radio, and other accessories. The alternator is crucial for maintaining the electrical system's operation, particularly after the battery has provided the initial power needed to start the engine.

While starting the engine, the battery does supply the initial energy required, but it is the alternator that ensures the battery remains charged after the engine has started. In addition, the alternator provides power to the vehicle's electrical components while the engine is running, making its role central to the overall operation of the vehicle's electrical system.