There are two sources of current in the car: the battery and the generator, which supplies voltage only

There are two sources of current in the car: the battery and the generator, which supplies voltage only when the engine is running. What is the purpose of both sources?

Automobile battery – a chemical source of direct current designed to power electrical consumers of a car such as lighting and signaling devices, relays, electric motors of wiper drives and the like, when the engine is not running. Consumers powered by a battery include a starter for starting the main internal combustion engine. That is, the battery is a necessary component for the initial start of the main engine.

The generator is an electric machine that converts mechanical energy of shaft rotation into electrical energy by means of electromagnetic induction. In a car, the generator receives rotation from the shaft of a running engine, therefore it generates electricity only when the engine is running. It is needed to power all electrical consumers of the car and recharge the battery while driving through a rectifier relay-regulator. That is, the generator does not allow the battery to discharge, but since the generator generates alternating current, and the battery is a constant current device, additional devices are needed to work together: rectifiers and stabilizers.