Abstract: A series-hybrid powertrain includes a range extender, a battery, an electric motor and a controller. The range extender may include an internal combustion engine and a generator. The powertrain has three modes of operation. In electric only mode, the battery powers the motor and the range extender is not allowed to operate. In forced charge mode, the range extender attempts to power the drive motor and also re-charge the battery if the battery is discharged to, or is found below, a specified charge. In hybrid mode, the range extender is operated by a controller that determines the output of the range extender in hybrid mode considering inputs that relate to the state of charge of the battery and the power consumption of the electric motor. Optionally, the controller uses fuzzy logic to determine the output of the range extender. The powertrain may be used in an industrial vehicle.