Methods and systems are provided for operating an engine, the engine coupled to a traction alternator for vehicle travelling. In one example, the method includes, in an off-highway vehicle running mode of operation, supplying current from the traction alternator to a traction motor via a traction inverter to propel the vehicle, and, in a starting mode of operation, supplying stored energy from a first energy source and a secondary energy source to the traction alternator to start the engine.