A method for controlling the temperature of a battery in an electric or hybrid motor vehicle by means of a system including a vapor compression circuit in which a first heat transfer composition flows, and a secondary circuit in which a second heat transfer composition flows, the method involving: —heat exchange between the battery and the second heat transfer composition; —heat exchange between the second heat transfer composition and the first heat transfer composition; wherein the battery includes at least one electrochemical cell having a negative electrode, a positive electrode and an electrolyte including a lithium salt composition, the lithium salt composition including: —at least 99.75% by weight of a lithium salt of bis(fluorosulfonyl)imide; —chlorides Cl—at a mass content strictly less than 20 ppm. Also a system for carrying out the method.