Can the car charge the battery when idling?
2 Answers
When the car is idling, it can charge the battery with the help of the regulator and voltage. However, since the engine is not operating normally, relying solely on idle speed results in relatively low power output. The battery, also known as a storage battery, is a type of cell that primarily works by converting chemical energy into electrical energy. Batteries require regular charging. If a car is not driven for an extended period, it should be started to charge the battery, as prolonged inactivity can lead to gradual self-discharge until the battery is depleted. Additionally, cars should not be exposed to extreme temperatures for long periods. High temperatures can cause the battery to overheat, affecting its storage capacity, while low temperatures significantly reduce the battery's capacity compared to normal conditions.
As someone who frequently works with cars, I can confirm that idling the engine does charge the battery. Once the engine starts, the alternator kicks in and generates electricity to replenish the battery. However, the charging efficiency depends on conditions: if the car is idling at low RPM, the alternator's output is limited, resulting in slow charging. If the battery is severely depleted, idling for hours may have little effect and could even shorten the battery's lifespan. In such cases, I usually recommend driving for 10-15 minutes at higher RPM for faster and more reliable charging. Regular maintenance is also crucial—check if the alternator belt is loose or use a voltmeter to verify that post-start voltage stays within the 13.5-14.5V range. Don't overlook ventilation; avoid charging in enclosed spaces like garages to prevent carbon monoxide buildup. Developing a habit of periodic battery health checks can prevent unexpected failures.