NOVELTY - The method involves utilizing a receptacle (12) in which electrochemical components of corresponding rechargeable electric energy storage batteries (11) in an electrical or hybrid traction vehicle are housed, magnetocaloric heat pumps (13, 23) associated to the receptacle and a heat exchanger (14) opened to an external medium. Calories are exchanged between one of the electrochemical components and the external medium by a coolant circulating circuit (15) that is coupled among the battery, the heat pumps and the heat exchanger.    USE - Method for thermal regulation of a rechargeable electrical energy storage battery of an electrical or hybrid traction vehicle (all claimed).    ADVANTAGE - The method ensures thermal regulation of the rechargeable battery of the vehicle in a precise, autonomous and permanent manner, with high energetic efficiency and low electrical energy consumption, thus increasing the capacity of the battery for optimizing the driveability and autonomy of the vehicle, and hence increasing the life duration of the battery, while respecting the environment. The method ensures the optimized exploitation of the battery, thus guaranteeing the stability of performances, maximizing the dischargeable energy and indicating the rest autonomy of the vehicle in a reliable manner. The method ensures the vehicle performance equal to that of an ordinary vehicle having heat engine, throughout the life of the vehicle and during storage conditions of the vehicle, while the battery is not discharged.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a device for thermal regulation of a rechargeable electric energy storage battery of an electrical or hybrid traction vehicle, comprising magnetocaloric heat pumps.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of a device for thermal regulation of a rechargeable electric energy storage battery of an electrical or hybrid traction vehicle.    Rechargeable electric energy storage batteries (11)    Receptacle (12)    Magnetocaloric heat pumps (13, 23)    Heat exchanger (14)    Coolant circulating circuit (15)