How long does it take to charge at idle speed?
2 Answers
Charging at idle speed takes about 1 hour. If the car is not driven frequently and you are worried about battery drain, it is recommended to start the car and let it idle for about 20 minutes every week. If the car is used regularly, the battery will be charged while consuming power, so there is no need to worry about the battery level being too low. If the car has not been driven for a long time, it may lead to battery drain or even damage. It is recommended to remove the car battery or disconnect the negative terminal of the battery when the car is not in use for an extended period. This way, the battery will not consume power when the car is not started.
I guess you want to know how long it takes to charge the battery while idling in place, and it really depends on the specific situation. Last time my battery was drained, after sitting for a few days, I had to idle for 35 minutes to barely get enough power; if it's just a slight discharge like forgetting to turn off the headlights, maybe 15-20 minutes would do. Factors include battery age—new ones charge faster, while old or problematic ones might take over an hour; temperature is also crucial—charging is half as slow in cold winters and faster in hot summers. Additionally, the engine idle speed is usually around 800 RPM, and the alternator output isn’t high, providing only about 10-20 amps of current, far less than the 40-60 amps when driving. Overall, this method is inefficient and not eco-friendly—prolonged idling wastes fuel and may cause engine wear. I suggest not sticking to this method; simply driving the car for 10 minutes at high speed is more effective, or using a portable charger. Regular checks on the battery and charging system can prevent similar issues.
