[Al Skierkiewicz]

Scott,
While not the best way to do this, I believe you are minimizing risk with the procedure you wrote. The issue with fully wiring batteries in parallel comes when they are mismatched in some way. The two batteries can actually discharge each other. If left unattended, this will result in total discharge of both batteries. While lead acid batteries are more tolerant of this fault, other batteries are not. Any search for RV battery isolators should show a variety of methods and products designed to charge and separate electrical loads with multiple batteries.