Abstract: The invention relates to a circuit arrangement (24) for a vehicle electrical system of an electrically driven motor vehicle (42), comprising: a high-voltage battery (26) for supplying power to an electrical drive machine (28) of the motor vehicle (42); a range extender (22), which is designed to charge the high-voltage battery (26) and which has a plurality of identical fuel-cell base modules (10) having interfaces for supplying reactants in the form of hydrogen and air; a switching device (32) for connecting the range extender (22), the circuit arrangement (42) having no DC-to-DC converter; a control device (36) which is designed to carry out the following steps after the control device has received an activation signal regarding the range extender (22): determining an operating point of the range extender (22) in dependence on at least one variable of the high-voltage battery (26); defining a setpoint value regarding the supply of the reactants to the fuel-cell base modules (10) and/or a setpoint value rega