First of all its not a converter you use its an INVERTER. sorry just one of those things that get under my skin. you can run the vest on an inverter, you'll have to get one that has an output of at least 500 watts because otherwise it won't support a vest at full capacity and you risk screwing up your vest due to low power. If you choose to purchase an inverter you can't run it though the cigarette lighter, it pulls too much current, you will either blow a fuse or you'll fry your cigarette lighters wires, use at least an 18 guage wire (as a rule, use a wire at least as thick as your plug to whatever you're plugging in, this can be used for extension cords too) Using an inverter does do a number on your alternator, depending on what you drive decides what it will cost to replace, it'll be a minumum of 150, if its a car it'll probably be more, suvs and trucks are easier to get too so they cost less for labor, the cars parts cost less though cause the alternator is smaller. which brings up another good point, the smaller the alternator the harder it will be on it. you'll have to hook up the inverter directly to the battery and run the wires into the car's cab which can be a pain in the butt to make it not look like crap. I have used an inverter in a car before and the only thing i can say is, if you do use an inverter, get a lifetime warranty on your alternator so it doesn't cost you when you blow it again