There some pics of my electrical system on this forum in the thread of Fitz’s build.
I have a 12v deep cycle marine battery (group 24), a WFCO 30 amp converter/charger which allows me to hook up in campgrounds. I also have a 50 watt solar panel tied into the system. It is semi permanently mounted to the top of my tongue box.
My system is far more than I need but it gives me plenty of options.