I tried this, blew out my interior light and 12v plugs in my Subie, the math doing 12v to 120 at 4amps says it takes too much (I don't remember there is a post somewhere about it). Most home circuits are 15 amp .so only 3 chargers at home per per circuit. I hope someone can expound on this for you. Don't bother even trying the abov suggestion.