Evaluation and Comparison of Battery Cell Balancing Methods

Cell equalization is required in series connected strings to prolong battery lifespans, ensure safe operation, and to enhance the usable capacity of battery packs. Several cell balancing methods have been proposed in literature to address cell mismatch in series strings. Amongst these, dissipative balancing is the simplest and the most cost effective solution. However, this has a low efficiency and restricted balancing speed. Capacitor balancing is popular energy transferring method with its simple control, compact size, and low price; but it also has low balancing speed. Finally, runtime balancing, which is a relatively new technique, shows good performance in terms of balancing speed, and efficiency with its high cost and complex controller. Using MATLAB/ Simulink, this paper compares dissipative balancing, capacitive energy transferring balancing, and runtime balancing methods in terms of balancing speed, efficiency, complexity, and cost, with suitable applications mentioned.