Battery Group Page
http://www.batteryspace.com/LiFePO4-40152SE-Cell-3.2V-15-Ah-150ASurge-Rate-48Wh-with-6M-screw-Termin.aspx

Section 5.3- Energy Storage



These ultra light batteries hit the market last summer and there specs are remarkable considering there weight. -
http://batterystoreonline.com/shop/index.php?main_page=product_info&cPath=397&products_id=10978&zenid=fc8fe741e207eaf83acac7590d2c91c2

These are batteries that were designed for use in electric cars and solar applications, although they are four times heavier than ultra light batteries, they have some very cool features that help so that the batteries are not destroyed during use.-
http://www.lithiumion-batteries.com/

Lithium Iron Phosphate (LFP)
https://en.wikipedia.org/wiki/Lithium_iron_phosphate

Wikipedia:

"Although LFP has 25% less capacity than other lithium batteries due to its material structure, it has 70% more performance than nickel-hydrogen battery. LFP’s improved capacity and stability draw automakers’ interests. For them, LFP can meet both the requirements of safety and battery life. Hence, hybrid vehicles are the critical market."