I watched a you tube video a year or so ago which showed a demonstration of a lipo fire. At that time, the alternative was to buy an expensive fire box or several lipo bags. If you can get a bag for $20, that's great. It's been awhile since I checked prices and the ones I found were around $39. I would have wanted a separate bag for each lipo so I wouldn't lose them all in storage, if one caught fire, but that's too expensive. The demonstration showed a lipo catching fire while charging, but the battery was locked in a metal "cash box". It seemed to protect everything fine, although there was smoke. So I bought a metal cash box for $26 at Walmart. But still can't afford to store each one separately. The (locking) metal cash box seems to do just fine, and I can store 5-6 batteries in it also, as well as use it to carry them to the track.

But, if I could get a $20 lipo bag, I think I'd do that now.