Overcharged/Damaged LiFePO4 Cell
This is a LiFePO4 Cell that was damaged from overcharging without an individual charge regulator, and no restraining plates. It is the reason for all the painstaking time spent building up of the LiFePO4 packs.
Note to self, never use a $200+ LiFePO4 Cell without a charge regulator installed. Also be sure and use restraining plates on the face ends of the packs, reference other photos in this photo set, to see how this has been accomplished.
The photo doesn't show it, but the bulge is the same size shape on both sides of the LiFePO4 cell.
When a LiFePO4 cell was dissected, that was damaged similar to this one, the internal plates had dry spots from the lack of electrolyte at those points. The plates had separated so much that the capacity had dwindled, and eventually it failed to hold a charge at all.
Trust me, you don't want to damage your LiFePO4 cells in this manner. Restrain the sidewalls and use charge regulators of some sort.