The active balancing method of lithium-ion battery pack is a technology to achieve power balance within the battery pack, which mainly solves the imbalance problem caused by the performance difference of each small battery during the charging and discharging process of the battery pack. The following are the main steps and principles of the active balancing method:

Charge shuttle: The active balancing method uses specific devices, such as capacitors or inductors, to release and store power from a specific battery unit, and then transfer it to another battery unit. When a battery unit has too high a charge, it will transfer the excess power to a battery unit with a lower charge to redistribute the power within the battery pack.

Intelligent selection: In order to achieve more efficient power balancing, the active balancing method also needs to intelligently select the battery cells that need to be balanced. This means that the control system needs to detect the power of each battery cell in real time and determine which battery cells need to be charged and which need to be discharged.

Energy transfer: Once the battery cells that need to be balanced are identified, the active balancing method starts the energy transfer process. The high-capacity battery unit will transfer power to the low-capacity battery unit through intermediate transition devices (such as transformers, inductors, or supercapacitors) until the two batteries reach or are close to balance.

Active balancing methods have significant advantages over passive balancing methods. Passive balancing methods typically dissipate excess power through resistive discharge, which generates heat and wastes energy. The active balancing method achieves balance through power transfer without consuming excess power, so it has higher energy usage efficiency and lower heat generation.

However, active balancing methods also have some challenges, such as requiring more complex control systems and more hardware components to implement. Therefore, when designing and implementing active balancing methods, factors such as performance, cost, and complexity need to be comprehensively considered.

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