A motor vehicle energy storage device includes a first electrical energy store characterized by a first characteristic voltage curve defining the open-circuit voltage of the first energy store depending on the relative charge state and by a first characteristic resistance curve defining the internal resistance of the first energy store relevant for a charge process of the energy store, and a second electrical energy store connected in parallel and characterized by a second characteristic voltage curve defining the open-circuit voltage of the second energy store depending on the relative charge state and by a second characteristic resistance curve defining the internal resistance relevant for a charge process of the second energy store. The voltage value ranges covered by the first characteristic voltage curve and the second characteristic voltage curve partially overlap, and the first and second characteristic resistance curves and the second characteristic resistance curve have exactly one intersecting point.