You can use our Comp heater with 12 volt, all you need is an inverter. I purchased one that is very small, compact, and inexpensive (20 usd) and works awesome with our heater. As far as the .12 engine heaters, we are working on them but we will never rush to bring a product to market. What alot of the Mcgiver types (which is fine) do not understand is the amount of R@D and time and money we put into developing our product. If our product was, and is so simple, surely someone would have come up with it years ago. Like most great products, there are certain formula's that make it work. Competition Heat is always looking at way's to improve our product and to bring new products to market. Our focus is none other than being the leader and company R/C racers look to for pre heating their racing engines.