An energy supply system for supplying at least first and second components of a motor vehicle with electrical energy. The energy supply system is arranged in the motor vehicle and has a charging socket (60). At least the first component an energy store and at least the second component is a consumer. The at least one first component has a first electrical voltage and the at least one second component has a second electrical voltage. To carry out a charging mode, the motor vehicle is connected via the charging socket (60) to a charging station with which current which either has the first or the second electrical voltage is to be made available. A first charging mode, a second charging mode and a travel mode of the motor vehicle can be carried out with the energy supply system (52).