In addition to the use of batteries, the structural characteristics are also divided accordingly, which are divided into maintenance-free batteries, dry-charged batteries, wet-charged batteries, sealed batteries, colloidal batteries, and so on. Most ordinary vehicles are maintenance-free batteries, which is the letter "W". Compared with the batteries that need to be added with distilled water in the early days, maintenance-free batteries are more convenient and worry-free.

    There is a general standard for batteries, that is, 12V voltage. This standard was established in the 1950s. Now small cars or light trucks on the market basically use 12V batteries to power vehicles, while heavy trucks have the high horsepower. Diesel engines require higher motor power when starting, so some engineers connect two 12V batteries in series to reach the 24V voltage standard for vehicles. A large 12V battery is divided into many "small cells", that is to say, the battery starting with 6 is composed of 6 small batteries. The voltage of each battery cell inside the battery is 2V, so the 6 battery cells are connected in series. There is a power supply voltage of 12V. The common fault in daily life is that the battery is broken. It used to be good, but suddenly it can't be used. It may be that the internal series unit of the battery is disconnected. If it is within the warranty period, it needs to be returned to the factory for replacement.