Thanks for the responses guys. The rig I currently have is a weekender. I pull a trailer behind my motor home out into the desert with my motor-glider, dirt bike, and other toys. I spend Friday, Saturday, and Sunday flying and riding till I have to go home again. When it gets cold I run the heater some. Between the heater, lights, laptop and cell phone charging, and other normal use, my battery (single) was not getting me through the night. Now hopefully with a bank of three batteries I can get through a night or two without having to run the generator.
I will save the Solar and golf cart batteries set-up for my next rig. It will be a full-timing rig that I will use 365 days a year so I will get much more use out of it. I think that for now I will just keep the Parallex charger that the rig came with. If the charge time to 90% on the battery bank takes too long then I may replace it. I printed out a copy of the owner's manual which does not specify voltage but does suggest that the 45 amp charger is at least a 2 stage rather than a single stage. I will have to hook up a VOM and test that.