A charger adapted for charging at least one energy storage device to be charged by means of an electrical charging power provided by an electrical power supply grid is provided. The charger includes a grid parameter detector unit adapted for detecting at least one electrical grid parameter of the electrical power supply grid and for outputting a grid parameter detection signal on the basis of the at least one detected electrical grid parameter. A control unit receives the grid parameter detection signal and determines a control signal, wherein a charging power adjustment unit adjusts the electrical charging power on the basis of the control signal.