Can the Car Charge the Battery at Idle Speed?
2 Answers
Vehicle idling can charge the battery, as long as the charging light on the dashboard is off, it means charging is in progress. Modern cars use alternators for charging, and the battery's power is mainly used to start the car, which consumes a significant amount. However, once the car is running, the battery is no longer being drained. The power consumed during startup is replenished through the car's charging circuit. Charging can occur at idle speed, but the charging current is relatively small. Generally, the battery capacity of a household car ranges between 54 to 60 Ah. The car battery capacity indicates the amount of power the battery can discharge under certain conditions, including discharge rate, temperature, and termination voltage.
As a driver with many years of experience, I often encounter battery issues. It's certain that the battery can be charged while idling. The alternator is driven by the engine and still rotates at idle speed, allowing current to flow into the battery for charging. However, the efficiency is not high—the low idle speed results in limited power generation. For example, after a deep discharge, it might take one or two hours of idling to recover. I recommend charging while driving, as higher RPMs generate electricity faster and are more fuel-efficient. Regular battery maintenance is crucial; driving periodically or using a charger helps maintain battery health and prevents starting difficulties. Short-distance driving is more efficient than idling for charging purposes.
