Thats what we think !!!
Today at the nats practice i put aside a peaked IB4200 pack after it peaked on my Checkpoint charger.
After a few ninutes i heard a loud SHHHHHHHHHHHHH and saw it had vented and quickly grabbed it and threw it to the ground, while looking for something to put over it a cell blew like a large firecracker.
No one hurt but a lot of us stunned.
So guys BE CAREFUL !!! with your batteries and dont take for granted that they are all good and safe .
Before i forget it was charged at 5 amps with a 3mv delta peak cutoff and a temp cutoff of 47deg/c the default setting on the charger.