Charging device for charging a supercapacitor

A charging device that includes (a) a DC to DC converter ("converter") that includes a converter control input and a converter output for outputting a charging voltage to the supercapacitor, (b) an adjustable voltage divider, (c) a controller that is configured to (i) sense a supercapacitor voltage, (ii) determine a first target value of the supercapacitor voltage, based on an internal impedance of the supercapacitor and on a nominal supercapacitor voltage that is lower than the first target value of the supercapacitor voltage, and (iii) during a first phase of a charging process, output a control signal via the control output and to the converter control input, to set the charging voltage to one or more values that once provided to the supercapacitor cause the supercapacitor voltage to reach, at the end of the first phase of the charging process, the first target value of the supercapacitor voltage.