The utility model provides a portable direct current battery charging outfit of electric automobile, simple structure, reasonable in design, convenient to use, safe and reliable. Its NULL cable that includes battery charging outfit body and N kind specification, the NULL cable one end of N kind specification sets up corresponding specification requirements's standard plug respectively, and the other end sets up NULL power connector respectively, be provided with a reference level signal common terminal, a N signal terminal and a plurality of power terminal in the NULL power connector, power terminal is used for connecting the NULL cable, the NULL cable one -to -one of a N signal terminal and N kind specification, and the signal terminal who corresponds with the NULL cable respectively with reference level signal common terminal short circuit, the battery charging outfit body includes the control unit to and the NULL power connection socket, ACDC power module unit and the direct current control protection that connect gradually and rifle head unit, NULL power connection socket pegs graft with NULL power connector and cooperates.