US Patent 9849871 Electric vehicle opportunistic charging systems and methods

A vehicle includes an engine arranged to output torque and an electric machine arranged to apply a reaction torque against engine output torque to generate power for charging a traction battery. The vehicle also includes a controller programmed to issue a command to adjust the engine output torque and an output speed corresponding to a predetermined optimal brake specific fuel consumption while providing power to charge the fraction battery, satisfy an accessory power demand, and propel the vehicle.