Embodiments provide a method and a system for determining cell imbalance
condition of a multi-cell battery including a plurality of cell strings.
To determine a cell imbalance condition, a charge current is applied to
the battery and is monitored during charging. The charging time for each
cell string is determined based on the monitor of the charge current. A
charge time difference of any two cell strings in the battery is used to
determine the cell imbalance condition by comparing with a predetermined
acceptable charge time difference for the cell strings.