The Phoenix Forum has had several threads relating to RV electrical systems and components which are topics of interest to me. I found the links listed below on another RV site and by exploring deeper found they contain additional information that some forum members may find useful. The articles are written by a marine electrician and contain practical information that is applicable to RVs and was garnered from years of actual experience. Some of the articles go into considerable depth. I include the links here in case there is interest in these topics.
http://www.pbase.com/mainecruising/deep_cycle_battery&page=1 This link provides information on different battery types such as gel, AGM, lead/acid etc. It also discusses deep cycle, starting, marine hybrid , and 6 and 12 volt batteries.
https://marinehowto.com/category/electrical/This link covers various electrical topics including battery use and charge monitoring meters. Some topics are marine specific but most apply to RVs as well.
https://marinehowto.com/do-i-need-a-solar-controller/This link provides some general information on batteries, solar panels, and solar controllers.
