Patent ID: 7689330

Claim:
A method for efficiently controlling an engine of a heavy-duty hybrid-electric vehicle of at least 10,000 pounds Gross Vehicle Weight Rating (GVWR) traveling in a direction, the heavy-duty hybrid-electric vehicle having a generator, an inverter, a propulsion motor, a first energy storage, and a control computer, the method comprising: enabling a function comprising an automatic engine turnoff function; determining a first energy storage first State Of Charge; determining a first vehicle propulsion power requirement associated with the direction of travel of the heavy-duty hybrid-electric vehicle; turning off the engine if the first energy storage first State Of Charge is above a first energy storage first State Of Charge minimum threshold and the first vehicle propulsion requirement associated with the direction of travel of the heavy-duty hybrid-electric vehicle is below a first vehicle propulsion requirement minimum threshold; and, commanding the generator to spin the engine to drive at least one Power Take-Off accessory.