Battery questions on Wolfpack 23pack15

[fishingkid]

I have very little knowledge on batteries. I have a 2021 Wolfpack 23pack15 trailer was purchased out of state in September 2 trips so far 1 to campground 1 boondock trip for 7 days 100 percent off grid. The last 2 days off grid batteries died faster than normal. Got home pulled batteries fully charged and stored in garage. Trailer went to the shop with batteries on for 3 weeks with battery switch in off position after returning trailer to storage I pulled and charged batteries 1 took longer than normal to charge both said full charged few days later installed batteries and unit would not start the generator hooked up to the truck fired right up. Charged batteries again took them to a battery shop he states batteries are not fully charged cannot load test possibly a bad cell suggest contacting manufacture for warranty replacement. They do not have any locally in stock 2 interstate smr 24 batteries. I have a trip this weekend so I am now scrambling to decide what to do. Going off grid for 3 days. I’ve researched these batteries appear to be bottom of the barrel for choice in my setup. I see people recommending 6v batteries but I assume I’ll need 4? And the cost is a huge jump talking around $1200 for 4 I plan to get 2 of the gopower 190 watt solar panels setup on top in the next year not sure if that changes what batteries I should go with or not? I have a nps 4500 generator on board. A local Costco has 2 of the interstate smr 24 and smr 27 in stock but can not warranty my current batteries. They quoted me $79 a battery seems cheap but not sure I want to do this every 6 months any recommendations?

[bikendan]

You don't need four 6v golf cart batteries. Two of them connected in series, create 12 volts.
Suggest that you Google "the 12 Volt Side of Life". It's a good primer on the two different RV electrical systems. It's also in the Forum Library.