1. The output voltage of 12V battery and 24V battery is different, and the voltage of 24V battery is twice as high as that of 12V battery.

If the AH of the battery is the same, the 24V battery is twice as large as the 12V battery.

2. The selection of 24V and 12V for automobile batteries is related to the configuration of car batteries and electrical appliances.

The battery of small cars and medium-sized cars is mostly 12V, and large and heavy-duty trucks have two battery configurations: 12V and 24V.

The 24V battery is equipped with a battery bank consisting of two 12V batteries connected in series.

The car is equipped with a generator to charge the on-board battery.

Therefore, if you want to charge the car battery, you should adjust the voltage of the charging battery to 12V or 24V corresponding to the battery.

Otherwise, the battery is wrong, which will cause the battery to be charged abnormally or even damage the battery.