The amount of time required to charge a car battery depends on the charger's amperage and the battery's capacity
. A fully depleted battery can take anywhere from 2 to 24 hours to recharge
. Car Battery Charging Times
- Fast Chargers (15-30 Amps) Fast chargers can charge a car battery in approximately 2 to 4 hours, but using a fast charger frequently can shorten the battery's life
- Standard Chargers (4-10 Amps) Using a standard charger, it can take 8 to 10 hours to recharge a dead battery fully
- Trickle Chargers (1-3 Amps) : It can take 12 to 24 hours to recharge a dead battery with trickle chargers, which are best for maintaining a charge over long periods, especially for cars in storage
- Driving Driving at full speed can take around 1 hour to fully charge a car battery
. It takes approximately 4 to 8 hours of driving at highway speeds to charge a car battery, but it will not reach 100% while driving
. Driving for 30 minutes to an hour can allow the alternator to generate enough power to charge the battery effectively
For a 12V car battery with a capacity of around 50Ah, using a slow charger (2A) will take approximately 25 hours to charge, a medium charger (10A) will take about 5 hours, and a fast charger (20A) will take about 2.5 hours
. To fully charge a 48 amp battery at 2 amps, it will take 24 hours, 8 hours at 6 amps, 6 hours at 8 amps, and almost 5 hours at 10 amps
. Charging a car battery at 20 or 50 amps can potentially damage the battery if it's dead, but it takes 2 1/2 hours to charge at 20 amps and 1 hour at 50 amps
