A battery pack is generally composed of several parts such as a battery (module), thermal management system, BMS battery management system, electrical system, structural system, etc., which play different roles in the battery pack.

The battery is the core of the battery pack and the only source of electrical energy. The battery cells of the battery pack are connected in series and parallel to form a high-voltage, high-capacity "large battery" to ensure sufficient power and range for the car. At present, electric vehicle batteries are mainly cylindrical and square in shape. Cylindrical batteries are mainly large cylindrical, such as models 21700, 4680, and so on. The size of square batteries varies, and the batteries used by different manufacturers are different. In addition, there are blade batteries like those launched by BYD, such as long knives, short knives, square knives, and so on.

Battery Management System (BMS): By collecting and monitoring data on battery voltage, temperature, etc., real-time feedback is provided to the automotive MES system to ensure that each battery can be charged and discharged efficiently and safely. The BMS system includes hardware modules such as master-slave board and BDU, and the architecture is generally divided into two types: distributed and centralized.

Thermal management system: Ensure that the battery operates within a reasonable temperature range, improve battery charging and discharging efficiency, and extend battery life. There are two types of thermal management systems: air cooling and liquid cooling. Currently, most enterprises mainly use liquid cooling. Liquid cooling can be divided into cold plate and immersion liquid cooling, with most using cold plate.

Electrical system: responsible for current transmission and detection control signals. Including various copper aluminum bars for connecting battery cells, high and low voltage wire speeds, and other components.

In addition to the above introduction, the battery pack also includes components such as the battery pack housing, upper and lower cover plates, but generally divided into the several major components introduced above, which together form a complete battery pack.