Can Idling Warm Up the Car Charge the Battery?
2 Answers
Idling the car can charge the battery, as the principle involves the engine driving the alternator to work during operation, converting alternating current into direct current that enters the car's battery. This is why, after jump-starting a vehicle with a dead battery, the vehicle still needs to idle for about half an hour. Here are some relevant details: 1. Generally, during winter when the ambient temperature is low, the car needs to warm up after starting. After warming up, the fuel and engine oil in the engine can reach their normal working state, which helps prolong the engine's lifespan when the car is driven afterward. 2. The warm-up time should not be too long; usually, about 30 seconds is sufficient. When starting a cold engine, the engine speed will be relatively high. Once the engine speed drops to around 800 rpm during warm-up, it is ready. 3. In daily car use, it is essential to develop a habit of regularly checking the battery. When the car's battery warning light comes on, promptly pull over to inspect the vehicle to prevent stalling or difficulty starting due to low battery power. If the car struggles to start because of insufficient battery power, methods like jump-starting, push-starting, or charging the battery can be used to start the vehicle. 4. If the car remains unused for an extended period, it is best to remove the battery to prevent complete discharge due to power leakage.
From my perspective, idling the car can indeed charge the car battery, as the engine at idle speed drives the alternator to generate current, which is then output to the battery. However, the efficiency is very low. The idle speed is usually only a few hundred to a thousand RPM, resulting in a small output power from the alternator and a charging speed as slow as a snail. If the battery is severely depleted or the ambient temperature drops below zero, idling may not fully charge the battery, wasting gasoline and time instead. Related issues include reduced battery performance in winter, requiring longer charging times; if high-power electrical appliances such as headlights or air conditioning are turned on, the current consumption increases, and idling charging may not keep up with the consumption. It is recommended not to idle the car for a long time; driving the vehicle for a few minutes after starting is more efficient.
