If it's aluminum, especially white or blue, it's a version 2. .... Somebody else would know more about the feasibility of this than I do, but it might be worth thinking about using a boost converter to get up to 14 or so volts even when the vehicle is off.
I love this thread, I’ve been thinking about a propex heater to heat my RV5 oztent or RTT for quite a while, but now I’m rethinking that based on this. Just spent a few hours watching the demo and subsequent teardown videos —quite informative!
I have a lot of experience running a boost converter with ham radios, and I would say that it’s not worth it given the teardown video that was shown earlier in the thread. Voltage is not really an issue for this unit, as he showed it going Down to 6v.
The voltage converters end up using a more of your stored energy, as the inefficiency for boosting the voltage does have a penalty, and just serves to deplete the battery quicker. With ham radios you actually need the voltage to get max RF wattage output to the antenna whereas here you don’t need the voltage.
What I would do, is add a low-voltage circuit protector (cut off) to protect the battery from going below 10v, especially in the cold. Else the cost of replacing batteries will get quite expensive...
maybe the display based newer units have this functionality built In? Somewhere I saw the LCD icon listing and it showed low voltage error. Not sure if that’s 6v or something more reasonable to not damage the battery.