Abstract: The present invention is a charging apparatus devised to make it possible with the help of another car to start a failed engine resulted from an old storage battery or from over-charging by inserting cigar jack in a car without opening the bonnet and without the issue of polarity arising. In general, enough current can't be attained even if storage batteries in two cars are connected through a cigar jack. This is due to the narrow difference between the voltage of the two storage batteries. Furthermore, sufficient current can not be attained and it takes a long time because the voltage drop caused by internal resistance in the cable is not negligible. To resolve such problems, the present invention includes a small-sized switch mode power supply, generates needed voltage from the power source and outputs the voltage overlapped to the supplying voltage, which creates an effective charging in a short time.