im planning a large build right now and was thinking if my alternator only puts out 250 or so amps and my wire is rated at 300amps is multiple runs really needed?

my plan is one DC or equal 270 amp alt( doubt i can find a dual alt for this car). 2 runs + and two runs - from the starting battery to my battery bank of 9 batteries running approx 10k watts.

Multiple runs may help reduce voltage drop.

If it was me, I'd run two sets of 1/0 from alt output stud to front battery, then two sets of 1/0 from front battery to your battery bank.

I probably wouldn't run any wires from the front to the rear for negative, just make sure I'd have good grounds.

Then I'd use one 1/0 wire from each battery to the next in the bank, considering how close there going to be.

But that's just me.

I would say, yes.

I would say, yes.

care to elaborate?

Usually you see people with multiple runs of 1/0 gauge and its not needed, unless your restricted to the number of batteries you have. If your running one battery in the rear then you will need more runs since your electrical is more dependent on front battery and alternator. If your gonna have a battery bank then 1-2 runs of 1/0 gauge to the rear will suffice. If you have numerous alternators then yeah it would help to have more runs from front to rear.