Battery not charging anymore

My doorbell battery has discharged after about 3 months use, the device is connected to a mains powered transformer which shows 20.4 volts at the doorbell but still the app tels me it’s running on battery not hardwired. This has only just started, when I first installed the thing the app said it was hard wired but not any more. What is going on?

Hi @user62209. Even with your Doorbell hardwired, it will still need to be charged every once in a while. Depending on the settings you have and the amount of activity your Doorbell sees, the battery can drain quickly. You can learn more about this here.