Kind of a Rube Goldberg set up and it could run a battery down powering the thing from off the car battery, but with a battery charger on the battery , It's fused and I can't see a problem with a fire happening if I keep enough baby oil in thing to keep the heating element well submerged out of air and likely just run it a several minutes at a time any way.
Actually I was wrong about the heating element being submerged under the oil . You are instructed to only put 16 oz of mineral oil in the bottom of can while pouring some of it over the wicking material that arches down to the bottom of can to wick up oil , with the heating wire coiled around the wicking material. I tried it and it makes smoke ok, but maybe will make even more as the wicking material blackens after more use or I put a different vacuum connector on the end with a 1/4" opening than the existing 1/8" hole on the end. I was worried about the paint can eventually getting metal fatigued and splitting where the regulator mounts to the side , so I cut an old rubber exhaust insulator in half and tie strapped it to the can just under the regulator and that bolsters the area and provides better confidence for the paint can to support the regulator long term without metal fatigue happening to the mounting area of the paint can seam, I also attached a $6 HF 1/4" swivel hose whip ,so I don't have a larger heavier 3/8" shop hose with air chuck hanging straight off the end that could tip the can over. The paint can smoke machine was $75 including shipping , a quart of mineral oil was around $10, Swivel hose whip about $6.50, 3 HF zip ties about 30 cents, an old exhaust insulator was free. Always a Possibility I might need to use my fire extinguisher sooner or later , but for now this budget set up will have to make do.