How Long To Run Your Car To Charge Battery. While idling older vehicles for 15-20 minutes may give them enough of a charge to restart this approach is generally not recommended. If the car is being driven on a motorway with high RPM then it will only take 30 minutes to get the battery completely charged.
Get a portable jump-starter. Lastly you may have heard that idling your car for 15-20 minutes is a good alternative method to recharge your battery. If your battery is fully charged you can run about an hour on the battery before it has too little power to keep the car running.
This way the car battery will continue charging.
Batteries slowly lose their charge when they sit idle and starting the car will drain it even more. As long as the mechanical action of the alternator is taking place. The answer is YES yes the car battery does charge while the engine is idling. Again assuming that the battery can still hold a charge.
