Originally Posted by Atthehop
It's not the draw it's the crappy factory wiring.
If you wire them properly, then the amp draw becomes the limiting factor. You do not want to exceed your alternators capacity, or you will be draining the battery rather than charging it. That can lead to a dead battery at the side of a trail in the middle of BFE.
Personally I prefer not to exceed 80% of capacity. Gives a bit of fudge room.