Published Paper Details:

Electric vehicles are increasingly promoted as environmentally friendly and energy-efficient alternatives to conventional internal combustion engine vehicles, yet their performance and safety depend critically on the behavior of the battery pack. When lithium ion cells are connected in series and parallel, manufacturing tolerances, temperature variations, and operating conditions lead to unequal charging and discharging, causing cell imbalance, reduced usable capacity, higher losses, and accelerated degradation. This study investigates a real-time Battery Management System (BMS) with integrated cell balancing to mitigate these issues in electric vehicle applications. An equivalent circuit model of a lithium ion battery is developed in MATLAB/Simulink, using experimentally derived open circuit voltage, internal resistance, and RC network parameters to capture both steady state and transient behavior during charge-discharge cycles. The work evaluates passive, active, and hybrid balancing concepts and proposes an adaptive passive balancing strategy that selects different resistor values based on state of charge differences among cells. The resulting BMS architecture performs continuous monitoring of voltage, current, temperature, and state of charge, while executing the adaptive balancing algorithm and enforcing CCCV based charging and protection limits. Simulation results demonstrate improved balancing speed, reduced energy loss, enhanced efficiency, and more uniform cell voltages compared with conventional passive methods, thereby supporting safer operation, longer battery life, and extended driving range in electric vehicles.