Novel Active Battery Balancing Methodologies for Lithium Batteries: An Experimental Comparative Analysis

Abstract

Inconsistency in the battery pack parameters results in an uneven state of charge (SoC). The active battery balancing method is an approach to equalize the SoC of the battery cells in a battery pack. In active balancing method, the battery having the highest SoC is made to equalize with the battery having the lowest SoC through the electronic circuits. However, it needs more cost and complex control circuits. To overcome this shortcoming, simple switching circuit‐based dynamic battery balancing techniques and row interconnected techniques are proposed. The proposed techniques are compared and analyzed with various conventional techniques. The experiments are conducted with 4.4 V, 6 Ah, 0.5 C lithium ferro‐phosphate battery cell and the battery pack consists of four cells. In the proposed techniques, the interconnections among the battery cells are altered using a switching matrix circuit. From the results, it is observed that the balanced row interconnected series–parallel dynamics and balanced row interconnected series–parallel have delivered superior performance under all the balancing conditions. Overall, the proposed technique enhances the battery storage capacity by 23.3% during the unbalanced SoC condition. The row interconnected series–parallel dynamics have achieved the average SoC of 96.14% under different balancing conditions.