NOVELTY - The device has a cooling circuit for cooling a traction battery (10) by circulating a coolant. A low temperature radiator (14) has two outputs, where one of the outputs ensures a single passage for allowing the coolant to pass toward electric elements formed of chargers (17, 19) and a power electronics (18) of an electric traction chain. The other output ensures two passages for allowing the coolant to pass toward the battery. The outputs of the radiator define a coolant circuit for the electric elements independent of the cooling circuit of the traction battery.    USE - Device for thermal management of a traction chain of a vehicle i.e. electric or hybrid vehicle.    ADVANTAGE - The device allows dimensioning of aerothermic frontage module without being constrained by adaptation of the hybrid or electric traction chain and avoiding generation of drastic overload of the cooling circuit while being likely to penalize the refrigeration of passenger compartment or to resize the condensation function and/or increase the performances and the dimensioning of the cooling circuit to dissipate additional calories present in low temperature fluid without having to too frequently resort to a secondary cooling loop. The device avoids the need for implanting heat exchangers in the frontage module. The device enables providing gain in fuel autonomy in case of a hybrid vehicle, autonomy in pure electric mode by reducing an energy bill for the hybrid or electric vehicle and durability battery, and improving usage consumption, robustness and repetitivity of performances. The device enables providing gain in availability of pure electric mode by reheating the battery, gain in establishment, costs, mass and reliability of operation. The device provides energy assessment of thermal management of battery, and avoids overcost of the frontage module.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view illustrating an operation of a device for thermal management of traction chain of vehicle.    Traction battery (10)    Chiller (11)    Low temperature radiator (14)    Chargers (17, 19)    Power electronics (18)