I will say this again... I see no issue with charging a Lead Acid battery to 80 or 90 percent (True Deep Cycle) several times in a row, say 2 or 3 weeks, but DO bring it up to 100% ASAP.. It does need to be full (and then some) at least once a week if possible (use generator)
Beyond that.. Little comment.
I ran my original Interstates 9 years,, But then I charge with a Progressive Dynamics 9180+ Wizard.. The new DEKA's are slightly largerm and I've also added more batteries.. The Interstates I had to water every Mother's day when new (mnore frequently after the first few years) the Deka's. Well I got 'em about 4 years ago watered them the first time last month.