Abstract: A cooling circuit with cooling liquid for lithium-ion batteries comprising a battery pack comprising a plurality of cells electrically connected with each other, suitable for powering an electric machine for traction, said cells being perimetrically delimited by external walls, at least one bag containing cooling liquid associated in contact with said outer walls of the cells. Advantageously, at least one bag is made of deformable plastic material so as to be counter-shaped to said outer walls to adhere perimetrally to said outer walls and the circuit comprises means of forced circulation of the cooling liquid through said at least one bag.