BATTERY UNIT COMPRISING COOLING MEANS

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).