Patent ID: 7795839

Claim:
A hybrid electric vehicle comprising: a drive train; an electric motor for driving said drive train; a power unit electrically coupled to said electric motor; an electric energy storage system electrically coupled to said electric motor, said electric energy storage system adapted to recapture energy from the braking of said vehicle so as to be capable of discharging and recapturing energy through a series of discharge and energy recapture events, and having a maximum charge level and an actual minimum charge level; and wherein said power unit and said electric energy storage system provide electricity to said electric motor for powering said vehicle; and an electric energy storage controller programmed to control said electric energy storage system by setting an artificial minimum charge level to an initial level above said actual minimum charge level, and, during a series of discharge and energy recapture events, to be able to adjust said artificial minimum charge level such that: (a) in the case where a discharge and energy recapture event results in the recapture of insufficient energy to recharge said electric energy storage system to said maximum charge level, said artificial minimum charge level is raised; and (b) in the case where a discharge and energy recapture event results in the recapture of sufficient energy to recharge said electric energy storage system to said maximum charge level, said artificial minimum charge level is lowered.