[Yetiman]

Maybe the 37 amp rating is the max. draw when they first fire up (inrush current)

Regardless, your charging system should have no problem at all keeping up; with them as long as they don't run for an hour straight after you shut the engine down.

Cobra's typically don't have much in the way of current consuming accessories (power windows, electronic everything, air conditioning etc.) so even the most basic charging system should be adaquate.