Right you guys are ... myself and a lot of folks don't have enough time to use their RV, let alone test it. I know how to test electrical stuff - that was my career - so I've probably had enough of it. It's time now to use the electrical stuff.
FWIW and BTW, how have I proved Mex's point? Perhaps, just perhaps, my RV batteries are indeed still at, or close to, full capacity - per my non-instrumented description above on how they perform at the present.
FWIW, I wonder what percentage of initial capacity was left in good old phone company batteries after 10-20 years on switching station standby duty? I'll bet a lot or all - assuming their electrolyte levels were properly maintained.
And Mena .... I'll bet that your RV batteries will enjoy a long and powerful life in light of how well you seem to be taking care of them. ;)