Not happy with factory supplied Interstate battery in my 2016 Max-S model with indoor kitchen. I have a 120 watt solar suitcase to keep it topped. But will not hold charge long enough boon docking. Using propane setting on Norcold fridge plus Alde on propane. Any suggestions under $200 for battery replacement? I think group 27 probably too tough to fit into front storage by simply changing battery case and platform.