HI in order to make things easier for my uncle I want to purchase a 12volt Warn wench. I would like to run it off a Vector battery start jumper, the kind you can plug in the wall and jump start your battery and carry it around. The guy at the FLAPS said forget it as the 12 volt Warn wench will not run off a batter jump starter. He said that it would not trigger the "demand"??? If you clip the cables to together from a wench or a truck battery how does the portable jump starter know the difference in types of demand? Would not the wench cause a "demand" like starting the truck????? T/C Steve