[major]

...
Jehu's video where he had a wire in a small parallel bundle completely burn as it was the shortest, and took the majority of the current (least resistance). ...

There's some flawed logic because copper resistance rises enough with temperature that current division between unequal lengths in parallel would equalize enough to prevent only one of the four from overheating to that degree. There most certainly was some other factor causing that failure.

Also I fail to see why someone would have made a multistrand cable from different lengths. It didn't appear they actually took a close look or dissected the crimps. Maybe all 4 strands were equal and all but the burnt one had pulled loose out of the crimped lug leaving only the "short" one to carry all current.

But copper parallels very well due to its positive resistivity coefficient. Lenght tolerance isn't normally a factor for wires and bars.

My opinions.

major

 

[major]

As long as your cable is properly sized and quality, I don't see a problem. If the load (or charge) share is unequal due to resistance of the 9 ft cable, then it will self equalize as the load (or charge) current diminishes because the voltage drop (I*R) in the cable goes to zero and voltage on both sides of the cable will be the same. If you're going to lose sleep over it just use a gauge size or two larger.

Regards,

major

 

[major]

I don't know if it'd cause trouble but your method leaves a large area in the battery side circuit to controller which will put inductance where you don't want it. Tesseract used to say to twist the power cables together on the input side of his controllers IIRC.

major