Can the engine charge the battery at idle speed?
2 Answers
Engine idling can charge the battery. When the car is idling, the charging indicator light on means: 1. No charging is occurring, and the battery is still discharging. Normally, when the charging indicator light is on, the battery will be charged, but the charging current is very small. 2. When the ignition switch is turned on, the battery provides excitation current to the generator through the ignition switch, fuse, charging indicator light, and diode, and also supplies voltage to the regulator's detection and control section. Extended content: When the engine idle speed is unstable, the following steps should be taken: 1. First, adjust the idle speed. If the problem persists after adjustment, check whether the idle jet and idle air jet are clogged. If the jets are clogged, clean them with gasoline or acetone and blow them through with compressed air. 2. If the jets are not clogged, stabilize the engine speed at a certain level and listen for air leaks at the intake manifold or the middle and lower gaskets of the carburetor. If leaks are found, they can be fixed by tightening screws or adding/removing gaskets. 3. If the idle speed is unstable and accompanied by a decrease in engine power, further check the spark plugs, valve sealing performance, and ignition timing. If necessary, perform maintenance and adjustments.
I think this is a pretty common issue. When my car battery was drained before, I relied on idling to recharge it, but it's important to note that the efficiency isn't high. As long as the engine is running, it can indeed drive the alternator to charge the battery, even at idle speed—just like when I kept the engine running while waiting in a parking lot, it slowly replenished the charge. However, idle RPM is low, so the charging speed is very slow. If the battery is already severely depleted, it might take hours to charge it halfway; plus, it wastes fuel unnecessarily and isn't environmentally friendly. The best approach is to drive a few kilometers after starting the engine, as this charges the battery faster and more effectively. If the battery keeps losing charge, it might be due to aging or electrical issues, so regular checks are recommended to avoid getting stranded on the road.
