I dont even know how I found this but google can do some strange things. I am not a welder, however this looks like something a welder would like to read about. Its basicly a MIG, ARC OR TIG welder that runs from your car/truck battery, I guess a "mobile welder" for what I can understand. Anyway the website kept me reading and I dont weld so here is the link for the welders out there , sorry if this is old news - but the MIG GUN is not ready yet so it seems new.
http://www.perfectswitch.com/installpics.htm
http://www.perfectswitch.com/installpics.htm