Patent ID: 7478692

Claim:
An electric vehicle comprising: an engine-driven generator; a battery connected to the generator; an electric drive motor propelling the vehicle, the drive motor being driven with electric power generated by the engine-driven generator and electric power from a battery; a residual battery power detector cooperating with the battery to detect a residual power capacity of the battery; an accelerator operated by a user to control vehicle speed, the accelerator outputting a control signal indicative of a desired motor speed set by the user; and a hybrid controller managing the operation of the drive motor based upon the control signal output by the accelerator and upon a signal from the residual battery power detector, wherein the controller is configured to operate the drive motor, for a given control signal value, at a slower rotational speed when the residual power capacity of the battery falls below an established lower limit than when the residual power capacity is greater than or equal to the established lower limit.