Since 2 months is the eufy doorbell wired and works; strange is that in the app ia battery charge image. Eufy helpdesk says there should be an option in your app; the only option which is on in the app is: “existed doorbellreceiver”. When you install the homebase there is also a question but that is the wireless connection between the homebase and the doorbell.
So during cold days the battery goes empty. No reload during 8 voltage but empty. And the wired doorbells notification on the app is: no doorbell because of empty battery".
WHY WHY; the doorbell is wired on the old doorbell (min 8 V) and works.
Please your solution
you should check into replacing your doorbell chime. that was my issue. the old doorbell worked because it doesn’t care about crap voltage. Eufy needs good solid voltage to the doorbell. I got a replacement on amazon last year and the doorbell doesn’t ever drain battery now.
your statement: “So during cold days the battery goes empty. No reload during 8 voltage but empty. And the wired doorbells notification on the app is: no doorbell because of empty battery”.
made me believe you had a battery doorbell that you optionally wired for continuous use like i did. in either case, a bad transformer on the houses chime could be causing your issue.
Its entirely possible to have a dead battery on a doorbell even if its wired.
When you wire a battery doorbell to existing circuits, it only trickle charges the battery. If your detections exceed the current draw that the battery is receiving, then the battery will discharge and eventually die.
Cold temperatures make this worse because even though its wired, the internal regulator in the doorbell cam will stop charging at 32F to prevent destroying the batteries.
Also, 8 volts at the doorbell is low. You either have to replace the transformer with a larger capacity or remove the existing hard-wired chime thats dropping the voltage. Your doorbell should have 18-24 vac at the terminals and about 25-30VA of capacity.