Originally Posted by 4kids3fish
My main concerns would be an electrically-based fire in the cabin and a fuel-based fire in the engine compartment.
Being only 12V the "electrical" nature of the former probably isn't that significant, and if the power wasn't immediately disconnected reignition via arcing doesn't sound too hard to handle. It would be a different matter in an accident however, where fuel spilllage and power-shorting could both be present.
Halon extinguishers were banned in Aust long ago - I had to hand a very nice one back in during the 80's.
Have you ever heard the saying "It's not the volts that kills you, its the amperage."? Sure a small wire will spark and the fuse will pop. That is what it is there for. But you take the main battery cable, the ground cable, or the altenator output wire and you have some serious juice there. I know of Jeepers who have made trail repairs by hooking up a few batteries in series and actually welded broken parts with them.
And don't forget, the batteries power the coils which can put out in excess of 50,000 volts. Obviously enough to ignite a fuel/air mixture. That is what they are there for.
But I agree with you, a class C fire in the passenger compartment would be bad, but also be very rare because of the fused protection and lack of readily combustible fuel. If one were to catch though, it could get very hot, fairly rapidly, spread quickly and be very hard to extinguish. Halon would be the preferred agent to catch this one quickly. An engine fire is more likely because of the highly flammable fuel available but it is easier to control and cause minimum damage with a simple extinguisher.
Of course, we have been talking about worse case scenarios. The best protection is prevention. Keep the electricity contained within the insulation and the fuel within the hoses and you should be OK. Be careful with batteries, be careful with fuel, no problems. A quote I have always liked is "Hope for the best but be prepared for the worst."
I didn't know that Halon extinguishers were banned and had to be turned in in Aussie. Over here you can still have them, manufacturers can still make and sell the extinguishers, they just can't make anymore Halon. They have to use what they have or use recycled Halon. I looked it up and we haven't made anymore Halon since 1994. That explains why Halon is so expensive.
The other interesting fact - The exception is Aviation. The FAA mandates Halon extinguishing systems on commercial planes. And the EPA has made an exception to the ban on the production of Halon for aviation use.