How much charge can idling for half an hour provide to the battery?

[SanRiley]

Idling for half an hour can charge the battery by about twenty percent. Automatic battery charging: Whether the car is in motion or idling, the battery will automatically charge. The engine directly drives the generator via a belt, so once the engine starts, the electricity generated by the alternator undergoes rectification and voltage regulation before directly charging the car battery. However, if the battery is severely depleted to the point where it cannot start the engine, a jump-start may be required. Precautions for idling charging: Avoid using other power-consuming devices during idling charging. When the car battery is low and being charged by idling, although the current is low, it is sufficient. But if high-power devices like air conditioning, high beams, or car audio systems are used during charging, they may exceed the alternator's maximum output power. This could overdraw the already low battery, leading to permanent damage.