I'm going to venture a wild guess that if you forget to charge, it will stop working, as it's probably not magical. A low battery alarm would be about the most

I'm going to venture a wild guess that if you forget to charge, it will stop working, as it's probably not magical. A low battery alarm would be about the most idiotic feature imaginable for a sleep aid, so hopefully they won't do that. Probably a blinking light on the host charger.