The present invention relates to a boost converter which can operate both in a capacitive and in an inductive mode. In the capacitive mode the converter operates as a charge pump circuit by making use of a set of switches and a set of capacitors. In the inductive mode the converter operates as a boost circuit and uses a sub-set of the switches and an inductor. The mode is selected by means of a selection terminal that is also used in the capacitive mode for coupling of a battery to the boost converter.