[scdrj]

All of this, plus you have not even added in all the potential resistance before you hit that grounding spot. Further, consider that is the source as DC current flows from Neg to Pos, not Pos to Neg. Not that it matters here. There is more going on than meets the eye, but the connection is apt to be more of a problem. If the PS pulls 125A continuous, thats crazy. Anytime you have that kind of pull, there will be heat. Heat means more resistance. More resistance means more voltage drop. More voltage drop will require more current to maintain the same power level. I'm sure the engineers are not stupid. There is more to it.