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

The primary role of an alternator in a vehicle is to charge the battery and supply electrical energy. As the engine runs, the alternator generates electricity, which is used to power the vehicle’s electrical systems and recharge the battery. This process ensures that there is a continuous source of electrical energy available for components such as lights, radio, and fuel pumps, even when the engine is operating.

While it is important to note that the alternator can convert AC power to DC power, which is necessary for the vehicle's electrical systems, its main function revolves around maintaining the electrical system's energy needs while the engine is running. Therefore, charging the battery and supplying power is the most comprehensive description of its duties.