Reliability Design of BMS with Peak Current Reduction and Constant Current Charging

This study presents a reliability-driven design for a Battery Management System (BMS) that incorporates a Supercapacitor-Based Peak Current Reduction Circuit (SBPCRC) and a charging circuit featuring a low-side Buck. The SBPCRC, reduces the peak current by 55 %, lowers the voltage and current stress on the discharge MOSFET, while maintaining its current capacity. Mitigating the impact of external voltage and current fluctuations on the lithium battery, it improves the system's reliability. Additionally, utilizing low-side current sensing achieves constant current regulation. A prototype circuit is built with eight lithium-ion batteries in a string. The experimental results show that the BMS with SBPCRC significantly reduces the peak current compared to that without, resulting in less current stress on the MOSFET. And the BMS with SBPCRC operates in constant current mode during charging. The results verify the feasibility and high performance of the proposed BMS.