Battery

Hi, My battery was showing low today so I charged it up. Left it charging for almost 8 hours and I have the full green light indicating that it's fully charged but now when I put it back into the doorbell its still showing up as low on my app. All my notifications has now stopped and I can no longer go to live view. If the battery is out of the device should I still be seening the little yellow icon on the app? I did also notice that my app updated this evening as well and could this be part of the problem? Has my app just frozen? Can someone please tell me how to fix it?