I got a goal zero 400 (non-lithium) for a steal at a close out vender. It powered my ARB 37 for a week, no issues @29 degrees. I was gonna do a dual battery setup, but didn’t like the inability to move battery system if needed to another vehicle. Non-lithium can be charged while driving from a 12v plug, kept it fully charged, going to install 2 boulder 30 panels once I figure out how / where I want to mount them.
Great to have it all in one system, no invertors, or isolation issues. I found two additional batteries that I can link to the 400 “base” unit and have a 1200 vs 400 for longer isolated trips.