Hopefully my experience will be helpful to others. I have had my doorbell wired for years and suddenly needed to charge the battery. After a few months of charging it every few weeks, I finally took it off the wall, took fine sandpaper and sanded the wires to make sure they would make good contact and reinstalled the doorbell. Been staying charged again.
I installed a wired doorbell on 1/4/2022 and am already having a replacement sent from Ring, but this is good to know for future use. Wires on my house are clean.