How many hours does it take to charge a car battery when the car won't start?

[SanSamuel]

If the battery is dead and you want to charge it using the engine, taking a 12V60Ah battery as an example, the charging method involves constant voltage with current limiting. Charge at 14.8V constant voltage and 15A current limiting for 16 hours, followed by 3A constant current charging for 4 hours, totaling 20 hours. The required charging time is relatively long. Here are some additional tips: The most familiar and effective emergency starting method is push-starting, but this is a last resort and should not be used frequently. This method can cause some damage to the engine and clutch, especially in automatic transmission vehicles, which should avoid using this method. To avoid being unable to charge when the battery is dead, car owners should keep a set of jumper cables in the car, which can be purchased at most auto parts stores.