A multi-stage charging device (102, 202) for a fuel cell comprising: a shaft that is supported for rotation about an axis; a first compressor wheel (180, 280) and a first compressor housing that cooperate to define a first compressor stage, the first compressor wheel (180, 280) being fixed on the shaft; a second compressor wheel (190, 290) and a second compressor housing that cooperate to define a second compressor stage, the second compressor wheel (190, 290) being fixed on the shaft, the second compressor housing defining a radial inlet, a shroud member and a volute member, the radial inlet being fluidly connected to a diffuser section and the volute member defining a volute passage therein that extends about the axis; a turbine wheel (161, 261) and a turbine housing that cooperate to define a turbine section, the turbine wheel fixed on the shaft in a back-to-back arrangement with the second compressor wheel (190, 290), the turbine housing defining a volute inlet member with a circumferential passage and a radial passage formed therein; a divider member comprising a plate that is positioned between the turbine housing and the second compressor housing, the divider member defining a boundary for the turbine section and the second compressor stage, wherein a first surface of the plate defines a portion of the radial passage and the circumferential passage and wherein a second surface of the plate defines a portion of the diffuser section and the volute passage; a motor that is disposed between the back-to-back arrangement and the first compressor wheel (180, 280); and wherein the turbine wheel (161, 261) is configured to be driven in rotation by exhaust from a fuel cell to assist the motor. a shaft that is supported for rotation about an axis; a first compressor wheel (180, 280) and a first compressor housing that cooperate to define a first compressor stage, the first compressor wheel (180, 280) being fixed on the shaft; a second compressor wheel (190, 290) and a second compressor housing that cooperate to define a second compressor stage, the second compressor wheel (190, 290) being fixed on the shaft, the second compressor housing defining a radial inlet, a shroud member and a volute member, the radial inlet being fluidly connected to a diffuser section and the volute member defining a volute passage therein that extends about the axis; a turbine wheel (161, 261) and a turbine housing that cooperate to define a turbine section, the turbine wheel fixed on the shaft in a back-to-back arrangement with the second compressor wheel (190, 290), the turbine housing defining a volute inlet member with a circumferential passage and a radial passage formed therein; a divider member comprising a plate that is positioned between the turbine housing and the second compressor housing, the divider member defining a boundary for the turbine section and the second compressor stage, wherein a first surface of the plate defines a portion of the radial passage and the circumferential passage and wherein a second surface of the plate defines a portion of the diffuser section and the volute passage; a motor that is disposed between the back-to-back arrangement and the first compressor wheel (180, 280); and wherein the turbine wheel (161, 261) is configured to be driven in rotation by exhaust from a fuel cell to assist the motor.