Ansul Extinguishers
Ansul Extinguishers are bomber, over built-
Link to Manufacutuer -
https://www.ansul.com/en/Products/hand_portable/redline_hportable.asp
If you are building the ultimate expdidition rig, why not put the best extinguisher made on it. Is it overkill. Yes, but most of us believe in overkill.
Do I have one in my truck? I would if I could, but I settled for a 2.5# AMEREX
Extinguisher that has been through 4 trucks since 1982. I get it serviced, and its still working. I have used the Ansul extinguishers at work and they are bomber. I do have a 10# Ansul in my garage.
The AMEREX link
http://www.amerex-fire.com/products/product/27
The general advantage of the cartridge operated extinguisher is that the main tank with the dry chemical is not under pressure. Most extinguishers fail due to a slow leak in the valve. The vibrations of heavy off road use can cause additional stress on the valves under pressure. The use of a pressurized cartrige solves this problem. Another advantage is that the extinguisher can be serviced without special equipment if use. Open the top, add dry chemical, install a new cartridge and its good to go.