The thing with Arlo Smart Activity Zones (on battery power) is that the camera will still detect with its PIR and will still record a video. The video is then analyzed by the Arlo servers and if all of the motion is outside the zone, it's supposed to discard the video and so you don't get a notification and you don't get a recording to your library. Unfortunately what this means though, is that your battery will run down quickly despite not having many recordings