ShoraipowerUSA has lithium/iron batteries. Half the regular size and 2 lbs.
I think you mean "lithium
ion". Same stuff cell phone and laptop batteries are made from.
Shorai seem to make a good product, but I can only recommend against them. Their customer service is some of the worst I've seen. One of their batteries malfunctioned in a customer's bike (which is totally understandable... even if problems are one in a million, somebody gets that one...) and took out the ignition box. Instead of standing behind the product and fixing what broke or offering to replace the battery, or even asking to have it back to test it themselves, they told the customer that their battery couldn't have caused the problem and then threatened to sue our shop and our service manager personally unless he changed his diagnosis.
In the end, the service manager didn't retract his statement, they didn't sue, we discounted the parts and basically did the labor for free to get the bike back on the road (since the customer paid for it), and the customer still left with a bad taste in his mouth. So yeah... that's why I'd recommend against using a Shorai battery. Good product. Lousy service.
Those Ballistic batteries are lithium ion, too. Same size/weight/output. I ran a similar setup for a couple of years made up of A123 cells that a hobby shop put together for me, and it worked great. I ran eight cells, but if I did it again, I'd go for twelve.
