Single AGM or 2 GC2???????

You need a "Charge Wizard" to plug into your Intelipower converter to cycle the charging currents properly so you wont boil your batteries like you are doing. You get what you pay for but I bought two Trojans t-125's 6 volt gc batts. By never letting them discharge below 50% I sold my TT with them them still going strong now 12 years old. My new to me TT 3 years with us, now has the same ones again. Yes they are pricey but look at the length of service. I wouldn't buy the Interstates as they would have been replaced already. We dry camp 50% or greater percent of the time. If your always on the generator I would also get an automatic water system for the cells. Trimetric sells a meter sc-2030 that montiors batt condition and has a temp sensor option. Unless your going to keep replacing batteries, you might want to invest in your power the way I did and not worry about it. This works for us.