Secondary accumulator charging/discharging for a motor vehicle using a controllable resistor

Electrical circuit for a motor vehicle, comprising:

• a primary system including a voltage-controlled generator, a primary energy accumulator coupled to said voltage-controlled generator, and at least one primary energy consuming device coupled to said voltage-controlled generator;
• a secondary system coupled with said primary system, said secondary system including a secondary energy accumulator and at least one secondary energy consuming device;
• wherein said secondary system further comprises a single control unit having a controllable resistor connected to said voltage-controlled generator, said control unit monitoring a charge condition of said secondary energy accumulator and, as a function of an actual charge condition of said secondary energy accumulator, controlling said controllable resistor and connecting and disconnecting said at least one secondary energy consuming device such that said primary system is not overloaded during a charging of said secondary energy accumulator and, during a discharging of said secondary energy accumulator, said secondary energy accumulator does not fall below a predetermined residual charge value.