I have a battery lead from a battery tender jr connected to my battery, I plan on running a heated vest through it. On the wires it says 18AWGx2c, 300V. I assume this means it's 18 gauge. Do I need a thicker gauge to get full power to a heated vest? The wire has a fuse, I'm not even sure what size but could I just put in a 15 or 30 amp fuse so it doesn't blow while powering the vest?