The invention relates to a charging device (1) and a method for charging an electrical energy store (2), wherein the charging device (1) has a
control unit (12) and a regulating unit (9), wherein the charging device (1) is set up to charge the electrical energy store (2) to a specified
state of charge within a predefined charging time and for this purpose to set a charging current and a
side reaction current of the electrical energy store (2).