A charging device for internal combustion engines includes a compressor part configured to compress drawn-in combustion air. The compressor part is arranged in an intake line of the internal combustion engine and is connected to the internal combustion engine via an actuatable mechanical coupler. An expansion part is disposed in a circulation system for a circulating working medium. The circulation system includes at least one exhaust-gas heat exchanger and a circulation pump such that the expansion part is driven utilizing waste heat from the internal combustion engine. An electric machine is connected to the expansion part so as to drive the compressor part. The electric machine is connected to the compressor part. An operational electric connection is disposed between the electric machine and a battery so that electric energy is stored during an energy-recovery mode or else so that electric energy is provided to drive the electric machine.