A disclosed method (and system) corresponds to rapidly charging a rechargeable device. An embodiment of the method comprises charging a first supercapacitor attached to a charging unit. In response to the device coupling to the charging unit, determining whether the charging unit is authorized to charge the device. The first supercapacitor discharging in response to the determining that the charging unit is authorized to charge the device, the discharging of the first supercapacitor resulting in a first current being generated. The first current is transferred to the device through an output of the charging unit for charging a second supercapacitor included in the device. The amount of the first current generated is regulated. In response to the to the voltage at the output increasing at a rate above a set threshold, reducing the rate at which the voltage is increasing.