Does Idling Recharge Car Battery. You will have to allow the car to idle probably for a couple of hours to charge the battery. Idling After a Battery Recharge.
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. When you park the car for 3 weeks consider disconnecting the negative battery wire from the battery. At idle the battery can take around 2 hours to charge up to 80 complete if it was flat and the alternator can generate 14 volts.
It will take around 20 min to put a hefty charge in a almost dead battery when the car is at idle and it jumps to around 5-10 min when the RPM is brought up a bit.
Not allowing your battery to charge will drain its power during idling. Again I encourage you to watch the video above this. Car batteries do get charged while the engine idles. Starting a car draws 100 to 300 amps to start a car and idling a car for 15-20 minutes will only replace 3-4 amps the car battery.
