smkettner wrote:$520 or $650 here: http://www.lithiumion-batteries.com/index.php
That's in the ballpark. The one (big) difference I can see between the two companies is: Lithium Pros actually design/build their own batteries (in TN--a couple hours drive from where the Leaf is built). I noticed there's a backlog/wait list for the Smart Battery product, so I don't know who designs/builds those batteries.
In addition, it looks like they have a "cover all bases" BMS where LP breaks theirs out into a "cell balance" and "cell balance+voltage protection=full" BMS. Nothing wrong with that, just a different approach to features/cost. Even though the Leaf is a much better "environment" than an ICE for a 12v battery, I definitely wouldn't buy a 12v Lithium replacement battery without some sort of integrated BMS (or it won't last).