DARKENING DEVICE

A concealment device comprises a housing, a screen, a winding tube, and an electrical energy storage device (33), comprising a battery (24) and two supports (37), fixed against an interior surface of a wall of the housing and maintaining the battery (24) in position inside the housing. The battery (24) comprises electrical energy storage elements (32, 32a, 32b) and two assembly elements (39). Each assembly element (39) is supported against one of the storage elements (32, 32a, 32b) along a longitudinal axis (X24) of the battery (24) and comprises a receiving zone (45). A holding element (42) of each support (37) is assembled with one of the assembly elements (39) at its receiving zone (45). The receiving zone (45) has an external diameter (Ø45ext) smaller than an external diameter (Ø24ext) of the battery (24). Furthermore, the holding element (42) has an internal diameter (Ø42int) smaller than the external diameter (Ø24ext) of the battery (24).