They shouldn't kick on until your in the 200s somewhere. 220 seems about right, maybe someone has the specs. Most aftermarket PCMs kick the fans on at like 195 to complement 180 thermostats.

To hook to a 12v source, unplug the fans. Then just jumper two wires from your batter to the fan. Simple as that. Getting to the plug is the hard part, the fans only have a positive and negative. Worst you could do is reverse polarity and spin the fan the opposite direction.