How to charge the car battery and how long does it take to charge if it is dead

The car battery should be charged in time when it is dead. You can use a charger to charge the battery. Generally, the battery capacity of a family car is about 60Ah, and the charging current required is one-tenth of the battery capacity, which is 6A. Charging with this current usually takes about 3-5 hours to fully charge. If you charge with low current, you need to charge for about 10 hours to fully charge.

If the car battery is out of power, causing the engine to fail to start, then you can use the battery jumper method to charge. Battery charging is to connect the battery of another car with a dead battery. After the power is transferred, the engine can be started, and then the internal generator is used to charge the engine while the engine is running. Generally, the engine needs to be idling for about 15-30 minutes. Make sure that the battery has enough power.

When using the charger to charge the car battery, the electrolyte inside the battery bubbling, indicating that it is fully charged. If it cannot be observed directly, it can also be distinguished by listening to it. Generally, the battery of a family car has a voltage of 12V, but the actual voltage will be slightly higher. Usually the no-load voltage is about 13V. Use a multimeter to measure it. When the battery voltage reaches 13V, it indicates that the battery is fully charged.