I brought a Ring doorbell soon after they first came out (very first version) in fact it was when they were mega expensive (which was before Amazon purchased the Company and knocked the stuffing out of the price). I recently purchased a power supply (from Amazon) advertised as okay for Ring door bells first issue. I wired it as per the instructions, it gives out an off load voltage of 21. 5 volts a. c. The problem is the internal (unremovable) battery discharges even with it connected to the power supply so I'm still getting reminders from Ring that the battery is really low. Any advice about what I can use to power my device and keep the battery charged or, am I wasting my time trying?