An intelligent power supply device includes: battery; a DC power bus coupled to the battery; a communication unit; a processor unit coupled to the communication unit; a voltage control unit coupled to the DC power bus and the processor unit; and an output connector. The processor unit is for receiving a setting command from a portable device via the communication unit, generates a control signal, and adjusts the control signal based on at least a voltage setting value indicated by the set command. The voltage control unit converts, based on the control signal, a DC discharge voltage that is provided by the battery at the DC power bus into a DC output voltage that is to be outputted at the output connector.