I have many different maintainer chargers, but only 1 of them is very consistent, 4 stage, temp compensated, actually 3 amp, and is designed and perfectly capable of fully charging over 200 AHs.
But if I had the choice, I would maintain any 12v battery(s) w/ a PD 9200 series RV converter charger. I don't know exactly what it does, but whatever it does, it does it RIGHT, trust me. Just check water each 6 months,.....notice I said "check", you won't add water once a year.
http://www.ebay.com/sch/i.html?_from=R40&_trksid=p2050601.m570.l1313.TR4.TRC1.A0.H0.Xbattery+tender+plus.TRS0&_nkw=battery+tender+plus&_sacat=0On edit, for 200 AHs, make sure the Tender is the "plus"....not "jr"