The invention relates to a charging device (1) for an energy store (2), particularly for a lithium ion battery in an electric vehicle (7), characterized in that the charging device (1) comprises a circuit (3) for adjusting the charging device (1) in a full charging mode or a parked charging mode, wherein the charging device (1) is set up for producing a fully charged state of the energy store (2) in full charging mode, and for producing a parked charged state of the energy store (2) in parked charging mode, wherein the parked charging state corresponds to a reduced charge state of the energy store. The invention further relates to a method for operating such a charging device (1) and an electric vehicle having such a charging device (1).