Thanks for the input guys. The balancer I use isn't an LBA10, but a Robbe 12S balancer (
http://store.modelpower.co.uk/robbe-...ncer-286-p.asp). It does use a 10A fuse like the LBA10 though, which blew on the moment of the short (I wasn't paying enough attention, and brushed the balancer's banana plugs together when plugging them in to the charger).
The Elites do perform great though as you say, Brian, and I usually just check pack temp with my hand every 5 or 10 mins; it's never been more than slighly warm (certainly no more than 110, tops), and the voltage always stays good under load until the very end of the run. It was the same low temp at the end of the last run. My transmitter warns me if it ever hits 3.3V per cell, even if only for a moment. The pack usually maintains at least 3.8V per cell for about 80% of the run, under high throttle.
The weird thing is though, that the pack sits in the tray the way up it is in the pic - with the bulge at the bottom, which is why I didn't notice it before. It uses a custom RC-M battery tray. The truck does do some pretty large jumps though, so I guess that could have contributed somehow. Then again, when I look closely, it does look like it might be the fourth cell that's puffed, pushing out the cell on the end. The pack's always secured in pretty well.
Aqwut, it's just the bottom "half" of the cell, which is mainly why I was curious (and decided to tap the font of experience that you guys are).
From what y'all saying then, sounds like physical trauma, or the slight overvoltage to that one cell during the charge. I'm kinda hesitant to try and break the pack up though (I know it's technically fine to do, but I don't trust myself to not mess up).
Lincpimp, that's interesting...how often have you seen it happen?