before they were small and used air, they were the size of a shopping cart and used inert bottled gasses from cylinders??
I had really good luck with a crappy Chinese plasma torch- only using the little 3 inch plastic water separator on the back of it...
It used a fair amount of air, and was 208-230V, but for trail repairs, wouldn't really be expecting clean cuts on 5/8 plate
In today's world of on board air, and people carrying bottled co2 on the trail, there has to be a way to make something small and useable that runs off 24 volt DC??