Method for controlling charge balance among cells while charging a battery array

A method for controlling voltage levels among cells while charging a battery array to a target voltage uses cell balancing modes employing respective charging currents. The method includes the steps of: (a) In no particular order: (1) establishing a parametric criterion for identifying each balancing mode; (2) identifying a performance parameter associated with selected cells for each balancing mode; and (3) establishing an exit criterion for each balancing mode; (b) ascertaining the onset of charging; (c) identifying the extant balancing mode; (d) employing the charging current for the extant balancing mode for charging; (e) for selected cells: (1) obtaining an extant parameter associated with the cell; (2) comparing each extant parameter with the exit criterion; and (3) repeating steps (e) (1) through (e) (2) until the extant parameter satisfies the exit criterion; (f) terminating the extant balancing mode; (g) repeating steps (c) through (f) until target voltage is achieved; (h) terminating charging.