Disclosed are systems and method for charging a fuel cell vehicle comprising a fuel cell, a rotating load, an energy storage, a contactor, a DC-DC converter, and a control unit. When charging of the energy storage is performed, the DC-DC converter connected to the energy storage is placed in a direct connection mode wherein the input voltage and the output voltage of the DC-DC converter are the same without voltage adjustment for directly charging regeneration electrical energy from a motor of the rotating load to the energy storage.