Speaking of Batteries...
Has anyone researched supercaps for starting batteries?
Easy Installation with the KSM Starting Module
Back a while ago, I ran across them and they looked pretty good. The supercaps could charge up from a nearly dead house bank enough to get the engines cranked. Also, they are smaller, lighter and never (10,000 cycles+) wear out.
I have never seen one in action though, with day in, day out use, but the demo I saw looked like a winning solution.