The active cell balancing transferring the energy from higher SOC cell to lower SOC cell, hence the SOC of the cells will be equal. This review article introduces an overview of different proposed cell balancing methods for Li-ion battery can be used in energy storage and automobile applications.
In a Battery Management System (BMS), cell balancing plays an essential role in mitigating inconsistencies of state of charge (SoCs) in lithium-ion (Li-ion) cells in a battery stack. If the cells are not properly balanced, the weakest Li-ion cell will always be the one limiting the usable capacity of battery pack.
Consequently, the authors review the passive and active cell balancing method based on voltage and SoC as a balancing criterion to determine which technique can be used to reduce the inconsistencies among cells in the battery pack to enhance the usable capacity thus driving range of the EVs.
Active balancing, also known as non-dissipative balancing, facilitates the transfer of charge from cells with higher SOC to either cells with lower SOC or auxiliary circuits. Ensuring balance among battery cells connected in series is crucial, due to the situation illustrated in Figure 1. the lowest SOC cell.
The BMS compares the voltage differences between cells to a predefined threshold voltage, if the voltage difference exceeds the predetermined threshold, it initiates cell balancing, cells with lower voltage within the battery pack are charged using energy from cells with higher voltage (Diao et al., 2018).
Individual cell voltage stress has been reduced. This study presented a simple battery balancing scheme in which each cell requires only one switch and one inductor winding. Increase the overall reliability and safety of the individual cells. 6.1.