ORIGINAL: jester_s1
LiFe's are very sensitive to being overcharged or fully discharged. They are more physically tough than Lipos, but that's it. That said, I have a couple of puffed ones in planes I fly now. They both cycle fine and maintain voltage fine, so I've kept using them. I saw something a while back that said early Lipo puffing was caused by water vapor that got trapped inside the cell casing and didn't affect the battery's performance. I have to wonder if that's the same situation with LiFe's as well.
In the magazine article where the author subjected the LiPo gasses to chemical analysis, they found the puffyness to be caused by expelled Nitrogen gas, that cannot work it's way out of the sealed covering.
I've taken many puffed packs, re-shrunk the covering, and subjected them to extensive testing...
All were good to their rated capacity...
That said, while puffed up, I do not believe they were overdrawn to an extreme.