A hybrid electric vehicle comprises an electric motor, a battery pack for the electric motor, a generator driven by an engine to provide electric power used for charging the battery pack, and a battery management for the battery pack. The battery management determines a current value of battery temperature (BT) of the battery pack and a current value of state of charge (SOC) within the battery pack. What are stored are a first set of varying SOC values and a second set of varying SOC values against varying BT values. The first set of varying SOC values are minimum SOC values required for the battery pack to produce a constant electric power output at varying BT values. The second set of varying SOC values are each indicative of an allowable upper limit to the quantity of electric charge that will accumulate in the battery pack due to operation of charging the battery pack with a constant electric power input at a corresponding BT value. The battery management provide an actuator command for control of electric power input upon charging the battery pack in response to the current value of BT, the current value of SOC, the first set of varying SOC values and the second set of varying SOC values.