Doorbell offline, won't power on after battery is charged

My Video doorbell 2 went offline about 1 month ago. 11/Sep/2020. On app battery shows as 36%, so I have removed anyway and put onto charge. The green charged light comes on straight away on battery pack to show it's charged(which it obviously isn't) I have charged for 5hrs then re-inserted and get no lights at all on ring doorbell. I have pressed the setup button with no response and also removed and re-installed the android app to no avail. The app still shows as offline, everything seems to be pointing to a faulty battery, but any help on this would be greatly appreciated. The doorbell is 6-8 months old.Kind regards