The invention proposes a wearable sensing device (100) comprising a sensing element (180) to sense physiological signs of a user wearing the device, electrical circuitry (170-172), air- or oxygen-dependent battery(ies) (110) comprising an air-inlet surface (111). The wearable sensing device further comprises a housing (130) of the sensing element (180), the circuitry (170-172) and the at least one battery (110), all functionally electrically arranged together.The housing (130) comprises casing elements (131, 131') arranged to lock the at least one battery (110) in a predetermined locking position. The housing (130) further comprises a base (136) and a cover (135) mounted to the base (136) in a manner and in such a way that an internal gap (132) extends between said battery air-inlet surface (111) and the cover (135). The base (136) and the cover (135) are further arranged such that said air-inlet surface (111) has an access to ambient air.The invention further proposes a wearable sensing device (100') arranged before use with sealing tabs (140) to protect said air-inlet surfaces (111) from air contact.
