Abstract: A battery unit includes a plurality of rows of cells, longitudinal members positioned between the rows of cells, a receptacle receiving the plurality of rows of cells and the longitudinal members, and a cooling system for cooling the cells. The cooling system includes: a dielectric-fluid circulation circuit positioned in the bottom of the receptacle and in the thickness of the longitudinal members, spray elements for spraying the dielectric fluid onto the rows of cells, the spray elements passing through an upper surface of the longitudinal members and communicating with the circulation circuit, and an extraction device for extracting the sprayed dielectric fluid passing through the upper surface and opening into the circulation circuit, and a dielectric-fluid cooling circuit connected to the circulation circuit.

Abstract: One aspect of the invention relates to a battery unit (1) comprising a plurality of rows (2) of cells, longitudinal members (4) positioned between said rows (2) of cells, a receptacle (5) receiving the plurality of rows (2) of cells and the longitudinal members (4), and cooling means (6) for cooling the cells. The cooling means (6) comprise: —a dielectric-fluid circulation circuit (7) positioned in the bottom (8) of the receptacle (5) and in the thickness of the longitudinal members (4), —spray means (9) for spraying the dielectric fluid onto the rows (2) of cells, the spray means (9) passing through an upper surface (10) of the longitudinal members (4) and communicating with the circulation circuit (7), —extraction means (11) for extracting the sprayed dielectric fluid passing through the upper surface (10) and opening into the circulation circuit (7), and—a dielectric-fluid cooling circuit (12) connected to the circulation circuit (7).