Hi @marc74. This is the Ring Community, a neighbor-to-neighbor support forum. The support team does not monitor this forum. If you have tried other chargers and are still having the same concern, give our support team a call at one of the numbers available here for further assistance. If you are outside of the US, please visit here to see how to contact support.
I suggest contacting ring and ask for a replacement. The same happened to mine after a year or so. Was hard work getting a replacement with Ring as their customer service is poor but I persisted and got a replacement. I found that after a year the battery was draining quicker and then it got to a point where it wouldn’t charge even thought it said it was charged to 90%. I’ve had the new doorbell now for 3 months and it’s only just been charged. Before it was every month