A powertrain includes a motor-generator and an auxiliary electric system. The powertrain also includes a first energy storage device disposed in a parallel electrical relationship with a motor-generator and an auxiliary electric system. Additionally, the powertrain includes a first switching device selectively transitionable between a first open state to electrically disconnect the first energy storage device from at least one of the motor-generator and the auxiliary electric system, and a first closed state to electrically connect the first energy storage device to at least one of the motor-generator and the auxiliary electric system. The motor-generator and the auxiliary electric system are operable regardless of the first switching device being in the first open and closed states.