I would think about a dryer element.
Dropping 6 v at 100a is 600 watts and .06 ohms. You could get there with parallel sections of a dryer element but I bet there is some voltage drop in the plating tank. You are not going to get 100a out of a battery long anyway. Are you sure you really need that much current? The problem with resistive current regulation is you waste a lot of energy in heat.


Greg Fretwell