Off, we have a couple on machines I don't have a place to mount the tank, so we use quick couplers for air hoses and hook the heater up on the machine, run the gas hose with a quick coupler on the end up into the cab or on the platform somewhere and just before we shut down for the night, sit a tank in the cab or wherever and hook up the hose with the quick coupler and open the tank, turn on the heater and let it heat up drawing juice off the battery when the engine is still running, after the heater element kicks out, which usually takes about five to ten minutes, the catalyst is hot and then the only electricity that's needed is to keep the gas solenoid open which is a few milliamps of power. Once its heating shut the engine off and your done for the night, in the morning, shut the heater off with a toggle switch and close the valve on the tank, unhook the quick coupler and put the tank in your pickup and use the machine, only hook up the tank when you need the heater, otherwise its in the truck or whatever you bring to the job site.
A 20 lbs cylinder will last for days, can't recall the amount they burn per hour, but its not much, 40-60 hours per 20 lb cylinder or something like that, I use two 30 lb cylinders mostly, so its weeks they'll run without worry, or if your only going to use them overnight, I can usually refill once or twice a month is all. To keep dirt out of the quick coupler, we use another blank end to hook up with a plug in it, never had an issue yet with any of them I have, we've also used quick couplers on the heater hoses and moved the heater from one machine to another and just use clips to hook to the battery instead of hard wiring the harness into the machine.
I use the RV tank auto changer to hook two tanks together, once one is empty it automatically switches tanks for me, that way one is empty before the next one gets used, makes refilling tanks much nicer. I've hooked up a couple tanks before and left it heat for over a week in bad weather when I wasn't sure when I would get back to the machine and use it. Otherwise it takes about three hours from starting the heater on the cold engine to 150 plus degree's on the engine if I wait till I get to the machine to start the heater up, takes about an hour and half to get the engine warm enough to start though if your in a hurry.
Google Hilton cordless heater, can't recall the guy there that you need to talk to, but he's about the only one there to answer questions, pretty sure he owns the operation anyhow, he can answer any question you have about them. The last I knew, they made two models, both were identical but one had more catalyst inside it, they called it the high output heaters, those are the one's I have, can't recall the cubic inches they'll heat but its far overkill for my needs but they work great.
Decades ago, a similar unit had a spark plug in them, worked on the same principle but these catalyst heaters are by far much better, virtually nothing to go wrong but a gas valve.
I've been told there are remote places that have standby generators that keep the engines warm 24/7/365 with these heaters, hook them up a 500 gallon lp tank and a solar battery charger/maintainer and when the power goes down, the engines are always warm and ready to go, not dependent on any electricity at all, that way anytime they can start and run/check the engine and the heaters never shut off, quite a few LP delivery trucks in my area have them on as well, never shut them off and tap into the vapor side of the truck's main tank to feed them. A few sawmills do the same thing with their stuff, then at the end of the day, drive up beside a large 500-1000 gallon tank, hook all the heaters up to a single manifold and there are no tanks on any machine, just depends on what your needs are. Best of luck.
