How Long To Leave Car Running After Flat Battery. However to be on the safe side a battery tender is your best option with the battery removed if you are planning to store your car for winter or long-term storage. Turn off the engines of both cars and disconnect the jump leads in reverse order to how they were attached removing the black lead from the car with the flat battery first and finishing by removing the red lead from the working car.
Assuming youre not driving at higher speeds just drive for 6-8. However after one hour of charging the car will be able to start. Then you could either leave the car running on the driveway or take it for a spin.
Make sure everything is off like the heater fan.
Depends how big your alternator is my camper has a beasty 160amp job I tend to leave it running for 40mins or so this will get the leisure battery up to 13v I dont think 20mins on a. Well the question which arises is how rarely do we use the car and how long before the battery flats out. IF the battery and charging system are in good condition and the car starts up normally meaning within a couple of seconds for any modern car in good condition it takes only a couple of minutes or so to replenish the small amount of energy stored in the battery that was used to start the engine. Car batteries usually last for about three to four yearsbut leaving your car sitting for far too long hastens the decay.
