A system includes a first energy storage system electrically coupled to a DC-link, and the first energy storage system comprises a first energy source that can exchange electrical power with an electric motor through the DC-link; a boost converter coupled to the DC-link; a second energy storage system that can be reversibly electrically coupled to the boost converter through a contactor, and wherein an operating voltage of the second energy storage system is less than an operating voltage of the first energy source; and the second energy storage system comprises both an energy battery and a second energy source, and the second energy source has an operating voltage that is higher than the energy battery and is lower than the first energy source operating voltage. A vehicle incorporating the system and a related method are provided.