I don’t understand why all the opposition to running off a single 30 amp 110v outlet using an appropriate 50 amp to 30 amp adapter? Yes, he will need to be conservative with loads. Battery chargers should mostly be on float. You could run a refer and a few other small draw items, lights, etc. I also don’t understand why the adapter will only power one leg? Is there something unique about Tiara panels? A 30 amp adapter should feed 110 v to both legs but, of course, you only have 30 amps total. I certainly wouldn’t suggest running this set up anywhere near 30 amps continuously but if it is just for storage what’s the issue? I’ve run mine on a 30 amp when traveling to marinas that only have them and it worked for me.