David

By any chance was the Li-Po cool/cold when you started charging and warm in the Rv?
Temperature has a big affect on Li-Po cells, not just performance. If you charge the pack when its cold and then leave it to get warmer the voltage will continue to rise and this could cause this. There are many factors that influence Li-Po "melt downs" we just need to understand them fully. I have hundreds of packs and have never been unlucky like David, I do keep the low cost Li-Po bags/sacks in the building and in the situation David had would place the pack in a bag as even after charging shows complete the chemical process continues. I've done plenty of testing on Li-Po bags and they will deal with fairly big packs if properly sealed, I use the Graupner charge case Paul008 shows as its a 1" thick ceramic walled case made for the job and has been proved up to the job. I will state that I only actually charge in it when I'm likely to be away from the charger/pack for even short times. I've never had a pack go up and I have some 14s set ups that are big number energy storage units! If you are with them you generally get a sweet smell as they start to gas and noise from the bags expanding, my experience is it takes and while and you can deal with it.

Biggest thing is no one was hurt and we can all learn from your loss, its a timely reminder of what can happen. There are plenty of internet articles from leading Li-Po manufacturers explaining some of the pit falls.
Everything we are surrounded by has Li-Po's phones, lap tops etc, these are no different, its just the process of dealing with charging etc is taken away from us and like the excellent PowerBox batteries they are housed in hard plastic cases.

Dave W