Auxiliary drive device, vehicle with an auxiliary drive device and method for operating a vehicle

The apparatus has a pedal crank assembly for introducing human power in a drive unit of vehicle. A control unit is provided to detect rotational speed of electric motor and to control electric motor, such that certain driving condition recuperation is performed. The kinetic energy is converted into electrical energy for charging a rechargeable battery. The control unit is provided to actuate electromotor during recuperation process, such that current rotation speed of electromotor is adapted to predetermined speed of electromotor. An independent claim is included for a method for operating vehicle.