The alternator provides power to power-consuming components when the engine is running and keeps the battery charged. The developed power of the generator depends on the frequency of rotation of the crankshaft. When the engine is idling, the alternator is running at approximately half of its maximum output. When the engine is idling but many power-consuming components are on, the alternator may not have enough power to keep the battery fully charged. In cold conditions, the ability of the battery to recharge is lower than in positive temperatures. This means that when the engine is idling for a long period of time and a large number of power-consuming components are connected, the battery may be discharged.
If alternator charging is disabled, the vehicle's power-consuming components are powered only by the battery, which can also lead to battery drain.
The generator generates alternating current, which becomes constant, thanks to the rectifier unit of the generator.
The rectifier unit is equipped with a built-in charging regulator.