LiPo out of shape

[Tansley]

I recently bought a Trackpower 4900 LiPo and charger. I've been well pleased with the performance of my B4 with 6.5 Novak Brushless Motor with Speed Pashion ESC, until this weekend.

After racing I checked the car and battery only to discover the battery is no longer flat, but the top & bottom have swollen noticably.

The max charge rate I used is 5amps, so I don't think it was overcharged, any ideas would be appreciated.