The biggest factor in battery fires in R/C Applications generally comes down to one thing...charging a battery too fast, it doesnt matter if it is NICD, NIMH, LI-ION or LiFE. Fast charging batteries creates more heat, which in turn increases the chance of cells catching on fire, or insulation of wires melting causing a battery short. I have seen people quote totally unrealistic charging rates for batteries. If your charging at anything over 1 amp, repeatably then you are definately risking a fire. The battery may be able to take it, but that certainly does not mean the wires or insulation can. One of the other mistakes people make is not actually waiting for a a battery too cool, before they try and ram another charge into it, so an already hot pack becomes hotter. Your better off having multiple packs and charging at lower rates. I spent a few years working in a company that used to build battery packs so Im not just going off my own personal experience but also that of the technicians who used to work for us.