I have had a PD converter with the Charge Wizard on my trailers since about 1998. I don't check the display very often because it is not necessary. The Charge Wizard takes care of the battery completely and all I do is check the water level about once a month or so.
Ours stays plugged in 24/7 for about 6 months of the year. The rest of the time is either spent moving or sitting in storage where the batteries stay on the tongue but are disconnected via a discnnect switch. Never had a single problem and the batteries last about 6 or 7 years or more.
Barney