You will always need to check water if you got with flooded wet cells.
If you go wet/flooded, get 6 volt golf cart batteries from Costco or Wally world. Lots of 12 volt batteries aren't truly deep cycle.....they are a hybrid.
To make batteries work/last better change over to a Progressive Dynamics converter. The one that came with the RV sucks.
If you want to go hard core and not check water, you need to get AGMs. It will cost you a tick over $300 per battery for 6 volt deep cycle Lifelines which is what I have after getting rid of the OE ones.
2011 Itasca Navion 24J
2000 Chev Tracker Toad