Question: how long does it take to charge a car battery?
Answer: Car batteries range from 40AH to 110AH, and alternators range from 45 amps to 200 amps. If you are using a battery charger, a 10 amp charger will take 4 to 11 hours to fully charge the battery, a 2 amp charger will take 2-4 days. Of course you don't have to get the battery to full charge to get it to start the car.