Just a friendly reminder: LiPo does not equal LiFePO4. The first is lithium-polymer, and the 2nd is lithium-iron-phosphate (the capital "O" = oxygen, the small "o" = 2nd letter in "polymer").
I think you guys are talking about LiFePO4 batteries, right? I think LiPo is used in cell phones, etc.
There's a stupendously informative post in the batteries section of CPF about all the different types of lithium batteries. 🙂