Getting back on topic .... I have a real jewel of a DW as she let's me do as I please re topping off, or not topping off, our RV's batteries. ;)
By the way Dan,
I keep our motorhome's engine starting battery on a BatteryMINDer Plus continuously while the MH is in storage at home. I got around 7 years out of the last FoMoCo engine starting battery doing this, and it probably wasn't bad when I just in case replaced it this summer.
I got around 8 years out of the last set of coach batteries keeping them on the stock 13.6 volt RV converter almost continuously while the MH was in storage at home ... and will do the same with their replacements that I just in case installed this summer. However, I intentionally use AGM coach batteries that have an actual specified float voltage of 13.6 volts to help insure that this continual float voltage doesn't harm them.
So ... to address your "Do I need to "top off" the battery if it is fully charged?" subject question: I don't know what is meant by "top off", but so far my RV batteries have had some kind of voltage on them for most of their lives and some of their lives have been long. FWIW, I've always called my coach's batteries "fully charged" when they won't accept any more current no matter what voltage I hook them up to ... at that point I continue to leave them hooked up to the stock 13.6 volt RV converter for floating.
