I'm turning my 2000 Explorer into my Plane Hauler. I have mounted 2 Trojan T-145 Golf Cart Batteries. They are isolated Hellroaring Tech Battery Isolator.
www.hellroaring.com/nodiode.php. I went with golf cart battteries because they are designed for constant discharge. They are mounted in custom boxes that are bolted to the floorboard and vented to the outside of the vehicle in case of accident. I have replaced to alternator with a 250 amp heavy duty unit that is used in Police Cars or other vechicles with lots of added electronics. All of the recepticals have been frame and battery grounded. No more dead batteries for ole Johnny. Will post pictures when finished.