A system and method for controlling charging of a plurality of battery cells includes a cell voltage detector determining a top-of-charge voltage for each of the plurality of battery cells. An imbalance circuit compares the top-of-charge voltage for each of the plurality of battery cells to an imbalance threshold and determines a first battery cell of the plurality of battery cells is above the imbalance threshold by an imbalance amount. A shunt control circuit determines an imbalance shunt time for the first battery cell based on the imbalance amount and controls discharging the first battery cell for the imbalance shunt time toward the imbalance threshold.