I probably should have gone with two batteries when I switched last summer. Had one new Interstate battery the came with the unit new in August. Unfortunately the factory or dealer only installed a 505mca battery which imo is puny at best and won't keep up with the large fridge with circulation fan that's always running. Also starts the onboard generator or should I say wouldn't after boondocking for about 5 hours. I found the biggest mca battery I could afford and switched them out. Happy days.
Interstate batteries are good as any but make sure they have the guts to keep you going. They do make some small ones that will still sell because their name is on the side.