Anyone using a portable propane heater?

I run an espar hooked up to 2 deep cell marine batteries on a relay that charge up while running and detach from the mains when the truck shuts down. I have a manual cutout switch from JC Whitneys that directs the exhaust up under the hood to the block when it goes below 20 degrees. and a carbon monoxide detector in the cab. my truck only idles under 20 degrees, and I'm toasty inside and don't run out of power

 

I use a piece of all thread and a hunk of hardware normally used on fencing. Just put it from pedal to under dash and adjust to whatever idle speed you need.

 

I know you're not supposed to, but I always keep a propane heater in the truck. I have the one with the low o2 sensor and I have a CO sensor. I hide mine. One time the temp got down to 15, the bunk heater had died in the middle of the night and I woke up freezing. I still couldn't idle the truck for more than 5 minutes. After about an hour of idling the truck to get the cab warm, I shut the truck off and turned on my heater. I left the window cracked with the small fan on and slept the next four hours with no problems. I didn't have to turn the propane on high. I took the truck to the shop the next day. You can do what you want but I'm not freezing to death for nobody.