Improving the Performance of Lithium Ion Batteries Using Cell Balancing

BMS (Battery Management System) monitors the battery&quots temperature, voltage, and current to determine the current state of the battery and protects the battery by responding to abnormal signals such as overcurrent and overvoltage. Additionally, the BMS uses cell balancing techniques to prevent fires and explosions caused by overcharging due to voltage imbalance between battery cells and improve the overall lifespan and safety of the battery. Therefore, in this paper, a test facility using a passive cell balancing technique was constructed to examine the charging characteristics of lithium-ion battery cells due to the voltage imbalance phenomenon. Using this test facility, BMS operation and cell balancing characteristics of 16 lithium-ion batteries in a state of voltage imbalance between cells were tested. In addition, the characteristics of batteries in voltage balance were examined through cell balancing after being used for a certain period of time. Therefore, the performance of the battery was compared by comparing the difference in charge amount for these two conditions (voltage unbalanced state and balanced state).