Been looking at the rolls 5000 series batteries. Could go with 6 of the 2 volt cells, or 4 big 12 volt units. Cost, weight, and capacity are about the same. I had 500 amp hours capacity on the boat, but that was pretty simple living. Would like to be able to run an energy efficient small house for 3 days between charging.
With heat, hot water, refrigeration, and freezer run by propane, and geothermal summer cooling, should be doable. Might as well add superinsulation, gravity pressured water, solar thermal mass, hot water pre heating, and mabe a few solar panels if the money holds up. I'm not convinced that solar electric panels are cost effective, but Oklahoma is august sure gets lots of sun.
I'm totally sold on computerised charging. The Balmar has some great features. Delayed alternator start up to let the engine warm up a little. Then it takes a minute or two to ramp up to full load. Can select for a pre programmed charge regimen for 4 different types of battery, or customise. Monitors and adjusts for both battery and alternator temperature, Can program scheduled equalization, detune alternator output, and more that I never used. This little gem can really do the job, and its rugged, waterproof, and even reasonably idiot proof. (built just for me)
Zeke