Hi, just wanted to to drop a line.
I am currently driving a 2005 Jeep TJ with an onboard custom built switching (solid state) battery charger, Group 24 Gel, no alternator and electric fan. My best MPG so far is 17.1MPG but that was before I removed the mechanical engine fan.
Check my switching power supply out, I have lots of pictures and discussion on MySpace.
http://www.myspace.com/reubengathright