Just wanted to throw in my two cents agreeing that this seems like a firmware issue. I made a post since I couldn’t find anything exactly like this thread, but now that I’ve found this thread, I’ll put this here with the troubleshooting I’ve done.
I have a Ring Video Doorbell 2 that’s always been hardwired to a 20VAC transformer since I got it in 2018. Until the past couple months, I have never had to charge it, but recently the battery has been draining even without any change in the average number of motion events.
If I take out the battery and plug it back in to “restart” the doorbell, it starts charging again slowly at a rate of about 8-10% charge per day. However, seemingly at random it will start draining quickly again at a rate of 15-20% per day. One time I tested the doorbell, it got back up to 44% before it started draining. Another time it got all the way up to 100% before it started draining again 1-2 days later.
It seems like maybe there’s a software bug that randomly triggers and then goes away temporarily after a reboot.
At first I attributed the battery drain to the cold since it first died when it was in the 10s and 20s Fahrenheit outside, so I took it inside and charged it, but now that the weather has warmed up, it’s still having the same issue. I also ended up doing a factory reset after I saw it had drained after the first time I charged it.
I connected the doorbell directly to the 20VAC transformer and bypassed my doorbell chime to make sure that’s not causing an issue. I measured the voltage from the transformer at the connections to the doorbell at 21VAC. But still having the same problem after doing that.