External power

This is probably a no-brainer, but I’m quite a bit confused:
I bought the Doorbell2 for my mother-in-law with the point given from the sales person, that it can be powered externaly. Since the manual doesn’t state that explicitly, I called the German support. The lady told me, that external power will not suffice, the battery still needs recharging. This support page (https://support.ring.com/hc/en-us/articles/115003495766-How-to-Connect-Your-Ring-Video-Doorbell-2-Directly-to-a-Low-Voltage-Transformer-Without-a-Pre-existing-Doorbell-) says that it is possible, to power externally. What is the real fact?

Hey, @ottO. The article that you referenced is indeed true, and if you would like to wire the Ring Video Doorbell 2 directly to your transformer, you can! In most cases, the power can keep the doorbell charging constantly preventing you from needing to recharge the battery often. If you’re able to wire the doorbell properly, then you should be fine. Keep in mind that our battery power Doorbell models are powered primarily by it’s battery and then recharged by the provided power from wiring. Too many events, poor signal strength, or live streaming videos for long periods of time can drain the battery.

Hi there it is odd they do not confirm that it can be powered and charged by a 12 volt ac transformer to which i have been using for a year now. No diode required just to terminals on backing plate.