Design Support


The need for cell balancing comes from the fact that cell-to-cell differences in self-discharge, capacity, and impedance can lead to different charge states among the cells. However, the charger terminates the charge based on the summed voltage only, which may leave some cells undercharged and others overcharged. To remedy this imbalance and to achieve the goal of having all cells reaching 100% state-of-charge at charge termination, it is necessary to reduce the charge added to the overcharged cell by creating a current bypass during charging.