Abstract: The device for assembling electrochemical cells together (6) side-by-side to form a battery is made up of two identical elements. Each of said elements comprises a base (2) supporting the ends of said cells, said base (2) being formed of an end wall (4) surrounded by an edge band (5), at least one elongate coupling prong (3) for coupling to the other element, which prong is integrally molded with the edge band (5) from which it projects perpendicularly, and complementary means (8, 9) co-operating to hold the two elements (1) assembled together and consisting firstly of a tooth formed on the prong of one of the elements and projecting in a direction that is substantially perpendicular to the assembly direction, and secondly of a recess in the edge band of the other element for receiving said tooth so as to snap-fasten.