Doorbell not charging

My doorbell battery has gone to zero, I took it off and have charged it all night but there is nothing there. I have unplugged and plugged into the back of the computer but here is absolutely no sign this thing is charging. I removed it from my app and have tried to re sync but i won’t as no power ?

For malfunction questions, please contact support, you will have more official solutions.

are you charging with provided cable and using homebase to charge or similar hi efficiency Anker chargers?
I would not recommend charging with computer USB port.