Energy storage system and method for the voltage adjustment of an energy store

An energy storage system (1), in particular for use in a motor vehicle, is proposed. The energy storage system comprises: an energy storage device (3) with a plurality of energy storage cells (5, 5a, 5b, 5c, 5d, 5e) connected in series; at least one switching device (7) associated with one or more energy storage cell(s) (5) for bridging the same; and a control device (17) with a control algorithm for controlling the at least one switching device (7), wherein the control algorithm is designed to actuate at least one switching device (7) in order to bridge at least one associated energy storage cell (5) when charging the energy storage device (3).