Hybrid powertrain with geared starter motor and belt alternator starter and method of restarting an engine

A hybrid powertrain comprising:

• an engine;
• a starter motor;
• a gear train operatively connecting the starter motor with the engine;
• a motor/generator;
• a belt drive train operatively connecting the motor/generator with the engine;
• a first energy storage device operable within a first range of operating voltage;
• a second energy storage device operable within a second range of operating voltage;
• wherein the first range of operating voltage is at least partially in common with the second range of operating voltage;
• a switching device selectively operable in an on-state and an off-state;
• wherein the first energy storage device and the second energy storage device are operatively connected with one another when the switching device is in the on-state and are operatively disconnected from one another when the switching device is in the off-state;
• a controller operatively connected to the switching device, the starter motor and the motor/generator;
• wherein the controller is operable to cause the switching device to be in the off-state and to power both the starter motor and the motor/generator with the first energy storage device during an automatic restart of the engine subsequent to a key start;
• and
• a selectively energizable solenoid;
• wherein the controller is operable to cause the solenoid to be energized to thereby operatively connect the starter motor with the engine through the gear train following cutoff of engine fuel occurring during an automatic shutdown prior to the restart so that the starter motor is operatively connected to the engine prior to the restart.