I'm sure its a question that you might have thought about once in a while....it did to me yesterday when I was doing some car prep.
Last year I had my trusty Orion 4800mah LiPo pack die on me. When connected to the charger, it wouldn't read a full circuit, so something had broken the connection inside the pack. I would have had a look at the time, but it was over 800 cycles old, never been balanced either, so time for replacement. I got an Orion 3800mah pack and relegated this to the bottom of my pitbox.
But, curiosity gets the better of me, and out comes the tools......
Under no circumstances should you do this unless you are prepared for the consquences. LiPo fires are dangerous, and will cause more damage than you can imagine. I take no responsibility for your actions.
Right, firstly, the pack.
Its a well-used Orion 4800mah LiPo that has served me well. Until the last time I used it, it was performing just as well as the day I got it. The only mods I did was to trim the top and bottom labels off the pack to aid fitting into a HB Cyclone (but that didn't help much, see the rub marks...
With the side decals removed, the pack is double-sided taped to the cells, so it takes a bit of prying before the lid is off. I used a pair of curved scissors to *carefully* trim up each corner and bend the sides outwards.
More careful pulling takes the lid off the pack:
Same process on the bottom, and the pack is free:
The remains of the case:
And finally, the possible culprit. It looks like one of those tabs broke as it wasn't soldered to the PCB like the others were:
Anyhoo, I took the cells apart and discharged them using a fan to flat, before salt bathing each, and disposing. Kinda boring, but techy to us geeks.