Does the alternator charge your battery when car is idling?

Yes, the alternator charges your battery when the car is idling. In fact, the alternator is primarily responsible for charging the battery while the engine is running. Here's how it works:

1. When the engine is running, the alternator is driven by the engine's crankshaft through a belt or chain.

2. As the alternator rotates, it generates electricity through electromagnetic induction. The rotation of the alternator's rotor inside a stator creates a magnetic field, which induces an electric current in the stator windings.

3. The generated AC (alternating current) electricity is then converted into DC (direct current) suitable for charging the battery by a component called a rectifier.

4. The rectified DC current is regulated by a voltage regulator to ensure that the battery is charged at the correct voltage. The voltage regulator prevents overcharging, which can damage the battery.

5. The regulated DC current is then supplied to the battery through a heavy-duty cable. The battery stores this electrical energy for later use.

So, even when your car is idling, as long as the engine is running, the alternator is actively generating electricity and charging the battery.