It is funny how now companies are selling high capacity Lipos. check out the links bellow of my 12000MAH that I have. I tested them for a few years before they lost all the charge. I had 2 packs, but I shorted one out to see if it would catch on fire and/or explode and it didn't. I even cut the cell open and nothing happened. The packs lasted 3yrs and a little over 1000 cycles. I had them since 1999.
I used one in my Stampede. I used the 2 packs in my EMaxx with the extreme carbon fiber chassis. The pack's measurements are:
200MM height (8 inches)
70MM width (3 inches)
25MM thick (1 inch)
It is also around the same weight of a 6 cell pack. Run time on my Stampede with a Lehner Basic 4200 and a 7020 (I think it is a 7020) was around 1hr. After 30mins. I was a little bored.
The battery of this size does have uses for it. With some brushless motors making over 4000watts, the capacity will be useful. It is also good for the big monster trucks.