Can the Car Charge While Idling?
2 Answers
Car can charge while idling. Idling refers to a condition where the engine is running but the car is stationary with the gear in neutral, consuming fuel without moving or performing work. In this state, the battery can be charged. However, the charging duration may be affected by other factors such as the use of high-power devices inside the car, turning on the air conditioning, or external USB power supply, all of which can increase charging time. Charging while idling consumes more fuel, and emissions during idling are highly polluting. Occupants should not sleep in a closed car with the air conditioning on, as incomplete combustion in the engine can produce carbon monoxide, which can accumulate to lethal concentrations inside the car. If charging is necessary, it is recommended to use a dedicated battery charger for the car's battery.
When the car is idling, the engine is still running and drives the alternator via the belt to charge the battery, but this process is indeed very slow. As a car owner who often tinkers with vehicles, I know the idle speed is low at around 800 RPM, and the alternator's output current is small, barely enough to maintain basic electrical needs. If the battery is already depleted, relying solely on idling to recharge may take over half an hour to show any effect, which is inefficient. I've also noticed that idling consumes extra gasoline—about half a liter per hour—making it neither eco-friendly nor cost-effective in the long run. Therefore, I recommend not relying solely on this method for emergencies. It's better to drive the car or use a smart charger for more reliable results. Regularly checking the alternator and battery voltage is also crucial to prevent minor issues from escalating.