Use AFFF, smothers most fires, has a cooling action which dry powder doesn't and washes off easily in the aftermath.
With all the fuses one wonders why there are electrical fires, the fuse should go long before a fire starts, however there are bits of electric string that are not protected between the battery and the fuse boxes which in these days of CANBUS are getting longer and more susceptible to damage my PC is slightly to the right of Genghis
2012 HSE SD4 In Orkney Grey now gone, best car ever.

Doing a bit more research because I carry 115 to 350 litres of fuel (120 litres currently, looking at 130 litres) I need a 2 kg extinguisher. 2 X 1 kg is not suitable. I can upgrade one of the 1 kg units for a 2 kg.

I wouldn't mind a 9 litre water air extinguisher for grass fires (say hot petrol exhaust issues) & I can recompress it from my air compressors. But where to store it & my payload weight issue is already a problem. Tempting one way or another! Procrastination, mankind's greatest labour saving device!

Acoustic insulation ARB TPMS 3xARB air compressors After cooler Air tank On-board OCD pressure air/water cleaning Additional 50L fuel Carpet in doors ABE 2x1kg Waeco 28L modified fridge Battery 4x26ah Solar 120w Victron MPPT 100/20 DC-DC 18amps 175amp jumper plug Awning 6x255/60R18