QUOTE=GrahamMc
Oh yeah, I also came across Firefly Batteries while poking around. They are actually located here in Peoria, IL. They will hit the market soon, but are essentially deep cycle lead-acid batteries with half the lead so therefore twice the energy density. They have prototypes in trucks and buses here now, so I am watching them with interest as the solution promises almost Lithium-Ion performance for almost Lead-Acid cost. (also a company called Axiom doing something similar but is further behind in getting to market).
Oasis Battery - fireflyenergy.com
Wow, I check out the entire web site, these batteries look a good at Nimh and lithium. Their next generation batteries will be smaller and stronger yet.