Battery balancing method in the battery pack

Crystal Battery Storage

During the battery manufacturing process, due to process problems or uneven materials, the battery capacity, internal resistance, voltage and other parameter values ​​are inconsistent; at the same time, when installed and used, due to differences in ventilation conditions, self-discharge degree and other conditions of each battery in the battery pack, the consistency of the battery will also be affected, which will not only directly affect the overall capacity of the battery pack, but also restrict the overall power performance of the battery pack.

In order to alleviate the problem of inconsistent battery cells affecting the performance of the battery pack, the battery system needs to be balanced. Currently, the main balancing methods used are active balancing and passive balancing.

Active balancing is balanced by power transfer, which is efficient and the balancing current ranges from 1 to 10A. However, active balancing has defects such as large size, many components, high cost and low reliability.

Passive balancing is balanced by using resistance heat release to discharge high-capacity batteries and release power in the form of heat to achieve the purpose of balancing. The advantages of passive balancing are simple circuit design, mature and reliable technology, and low cost, while the disadvantage is small balancing current.