A Passive Battery Management System for Fast Balancing of Four LiFePO4 Cells

In this paper, a Battery Management System (BMS) is designed and implemented to enable fast balancing during charging of four Lithium Iron Phosphate (LiFePO
₄
) cells connected in series, designated to replace the classical Lead-Acid battery of a vehicle. The BMS detects when the battery pack is charged and it enables passive balancing of charged cells, which are bypassed through high power resistors. The measured parameters (voltages, current, and temperature) and charging/discharging states can be displayed on LCD and transmitted to other Electronic Control Units (ECUs) using Controller Area Networks (CAN).