Design and Development of Battery Cell Protection System on LFP Battery Pack Using Bypass Techniques

Energy storage is experiencing an increasing demand. One example of this is the demand for batteries, particularly in the case of lithium batteries. Unlike other types of batteries, lithium batteries offer numerous advantages such as high energy density and easy maintenance. The common applications of lithium batteries are in the form of battery packs used in electric vehicles and renewable energy storage. However, battery packs have a drawback, which is the voltage imbalance among individual battery cells during high charging and discharging processes, leading to suboptimal power utilization and potential damage to the battery cells. Therefore, the development of a battery cell protection system using an active bypass technique is necessary to address the imbalance issue during charging or discharging processes, which cannot be achieved by passive or traditional active balancing methods. This research focuses on the battery cell protection system for battery packs using the active bypass balancer technique, aimed at mitigating cell voltage imbalances. The results of the device design demonstrate that the active bypass system effectively halts the rate of voltage increase or decrease in cells that have reached their maximum or minimum voltage thresholds. This system can maximize battery capacity utilization by up to 8.25%.