I've built several cabinet style incubators now and they work great so I never change the design much from 1 build to the next. What I've always wanted to do however was build one that can run on a battery backup. The problem is, right now I use 250 watt heater coils that operate on 120vac. I can find 300watt heater coils that run on 12vdc but 250 watts at 120 is roughly 2 amps. You've probably already done the math but 300 watts at 12 is 25 AMPS! What am I missing.I know this has been done before so i have to be overlooking how it's done. My incubators are always duel sided (one side for incubator one side for hatcher) so that's 50 amps just for heat. Since your going through a 12v power source and running 120vac most of the time am I still just pulling 2.5amps (roughly) to the power source then 25 amps from the source to the heater coil?