Thermal management device for the batteries of an electric or hybrid vehicle

A thermal management device for an electric or hybrid motor vehicle is disclosed. The thermal management device includes a reversible circulation circuit configured to circulate a refrigerant fluid. The reversible circulation circuit includes a main loop, a first bypass branch, and a second bypass branch. The main loop includes, in the direction of circulation of the refrigerant fluid, a compressor, an internal heat exchanger configured to directly or indirectly heat a flow of internal air en route to the vehicle interior, a first expansion device, and a first heat exchanger. The first bypass branch includes a second expansion device disposed upstream of a cooler. The cooler is configured to cool the batteries and/or the electric powertrain of the motor vehicle. The first bypass branch is connected in parallel at least with the first heat exchanger.