Energy-saving operation for an energy supply system with battery storage

A mobile energy supply system comprising:

• a plurality of battery modules that can be connected in series in a controllable manner to supply different voltages at an output of the energy supply system, and
• a control unit for activating the battery modules,
• wherein each battery module comprises:
• an input connection and an output connection,
• a battery unit, and
• a bridge circuit which is provided between the input connection and the output connection and is designed either to connect the battery unit to the input and output connection (battery mode) or to connect the input connection to the output connection by bypassing the battery unit (bypass mode), and
• wherein each battery module is designed to be controlled in an operating mode and an idle mode, wherein in the operating mode the bridge circuit can be switched into the battery mode and the bypass mode, and in the idle mode the bridge circuit is placed in a state with minimum energy consumption.