rjxj wrote:
The original wiring is about 30 feet of 6 gauge. I have installed a 4 gauge wire straight from the battery to the converter during this charge/test and the length is about 15 feet
15 feet is too far for 4 AWG to keep the PD near 55amps. Better than 6 AWG though! You can improve things by leaving that 15 ft of #4 on the pos path and using the frame for the neg path (as now?) by running another 15 ft of #4 to parallel that first wire. That will much reduce the total R of the pos path and the frame already has decent low R.
You can also run more wire to parallel the frame path on the neg side to improve the R on that. However the payback isn't as great as doubling the pos path, since the frame already has low R.
The R that counts is the total R of the pos and neg paths, so improving just the pos or neg path is a help. If you reduce the R on both even better but they don't have to be even R. It is the total that matters.