Circuit arrangement for a vehicle electrical system of an electrically driven motor vehicle, comprising - a high-voltage battery for supplying power to an electrical prime mover of the motor vehicle; - a range extender which is designed to charge the high-voltage battery and which has a plurality of identical fuel-cell base modules each having a plurality of fuel cells connected in series and interfaces for supplying reactants in the form of hydrogen and air; - a switching apparatus for connecting the range extender, which apparatus is designed to connect the high-voltage battery and the range extender in an electrically conductive manner to one another without a DC-to-DC converter in the form of a parallel circuit; - a control apparatus configured to carry out the following steps after said control apparatus has received an activation signal regarding the range extender: - determining an operating point of the range extender depending on at least one variable of the high-voltage battery; - defining a setpoint value regarding the supply of the reactants to the fuel-cell base modules and/or an operating temperature of the fuel cells on the basis of the determined operating point; - controlling a system designed to provide the reactants in accordance with the defined setpoint value if the setpoint value concerns the supply of the reactants, and controlling a system designed to control the temperature of the fuel cells in accordance with the defined setpoint value if the setpoint value concerns the operating temperature; - controlling the switching apparatus so as to connect the range extender, only after the setpoint value regarding the supply of the reactants has been reached, if the setpoint value only concerns the supply of the reactants; - controlling the switching apparatus so as to connect the range extender, only after the setpoint value regarding the operating temperature has been reached, if the setpoint value only concerns the operating temperature; - controlling the switching apparatus so as to connect the range extender, only after the setpoint value regarding the supply of the reactants and/or the operating temperature has been reached, if the setpoint value concerns the supply of the reactants and the operating temperature. - a high-voltage battery for supplying power to an electrical prime mover of the motor vehicle; - a range extender which is designed to charge the high-voltage battery and which has a plurality of identical fuel-cell base modules each having a plurality of fuel cells connected in series and interfaces for supplying reactants in the form of hydrogen and air; - a switching apparatus for connecting the range extender, which apparatus is designed to connect the high-voltage battery and the range extender in an electrically conductive manner to one another without a DC-to-DC converter in the form of a parallel circuit; - a control apparatus configured to carry out the following steps after said control apparatus has received an activation signal regarding the range extender: - determining an operating point of the range extender depending on at least one variable of the high-voltage battery; - defining a setpoint value regarding the supply of the reactants to the fuel-cell base modules and/or an operating temperature of the fuel cells on the basis of the determined operating point; - controlling a system designed to provide the reactants in accordance with the defined setpoint value if the setpoint value concerns the supply of the reactants, and controlling a system designed to control the temperature of the fuel cells in accordance with the defined setpoint value if the setpoint value concerns the operating temperature; - controlling the switching apparatus so as to connect the range extender, only after the setpoint value regarding the supply of the reactants has been reached, if the setpoint value only concerns the supply of the reactants; - controlling the switching apparatus so as to connect the range extender, only after the setpoint value regarding the operating temperature has been reached, if the setpoint value only concerns the operating temperature; - controlling the switching apparatus so as to connect the range extender, only after the setpoint value regarding the supply of the reactants and/or the operating temperature has been reached, if the setpoint value concerns the supply of the reactants and the operating temperature.