Abstract: A method for operating a hybrid drive device of a motor vehicle is disclosed, wherein the hybrid drive device includes an internal combustion engine, which can be operatively connected to a first axle of the motor vehicle, a first electric motor, which can also be operatively connected to the first axle of the motor vehicle, and a second electric motor, which can be operatively connected to a second axle of the motor vehicle. The electrical energy used for operating the second electric motor is generated in a first mode of operation by the first electric motor driven by the internal combustion engine while increasing the output of the internal combustion engine, and in a second mode of operation is derived exclusively from an energy storage device for electrical energy.

Abstract: A method for operating a hybrid drive device of a motor vehicle is disclosed, wherein the hybrid drive device includes an internal combustion engine, which can be operatively connected to a first axle of the motor vehicle, a first electric motor, which can also be operatively connected to the first axle of the motor vehicle, and a second electric motor, which can be operatively connected to a second axle of the motor vehicle. The electrical energy used for operating the second electric motor is generated in a first mode of operation by the first electric motor driven by the internal combustion engine while increasing the output of the internal combustion engine, and in a second mode of operation is derived exclusively from an energy storage device for electrical energy.

Abstract: It is known to charge the battery in a hybrid vehicle with a generator such that the efficiency (electric power per fuel quantity) is maximal. It is known that the consumption-optimized mode can be terminated in order to charge the battery faster. A mathematical calculation rule is applied to the optimal value of the efficiency in order to determine a value for an efficiency which then indicates a load point shift for the internal combustion engine. In particular, constant percentages can be used which are applied to the inverse efficiency.

Abstract: An electric battery of a hybrid vehicle can be heated by alternately discharging and charging the battery during a cold start, wherein the battery initially does not supply power to drive the vehicle. Heating the battery can also be used to simultaneously change the charge state of the battery. The heating can be started immediately at the cold start, without the need to first bring the electric battery to a specific charge state.

Abstract: It is known to charge the battery in a hybrid vehicle with a generator such that the efficiency (electric power per fuel quantity) is maximal. It is known that the consumption-optimized mode can be terminated in order to charge the battery faster. A mathematical calculation rule is applied to the optimal value of the efficiency in order to determine a value for an efficiency which then indicates a load point shift for the internal combustion engine. In particular, constant percentages can be used which are applied to the inverse efficiency.