but if u do the big 3 u could just run more power ... like 2or3 power and not the ground cus the big 3 ground the chaz no
big 3 mostly helps with voltage drop and is kinda a must for a ho alt
and with the multiple runs of power and ground wire is because 1/0 wire will only let at max around 300amp of current flow,and if u have amps that need around 500amps or so to run "efficiently" u will need less resistance thus more power runs
for these amp kits that say "up to 1800w max" is for amps that are raited at "1800w max" witch they dont acually do
like 4guage, i wouldn't try running more than a good 800wrms with it, 1/0 i have in my truck im only running 1000rms but can work with around 1500 to 2000 but with other electrical upgrades
but once u get big power like 4 or 6 3500w amps that pull around 300-400amps u will need the power wire to be sufficent to run it but with extra batteries u would need big 3 to help feed the power back to the batteries to feed ur amps
and with multi runs of power and ground helps get rid of that "how good of a ground is my chassis and what knot" because with grounding ur wires to chassis ur going threw welds and rivits and bolts and what knot that u dont acually know how well was put together so ur running the risk of insufficent grounding and this is why most people dont ground to sheet metal on a car like the floor and what knot due to this, thats why most people find a hole or make one and ground str8 to chassis to better the grounding but with a run of ground from front battery to back will take out the risk of not enough current flow and give u a better current signal and wont damage ur equitment
im going to run a ground from front to back once i get a lil cash rounded up
and most people dont know but a cars electrical system works backwards while running, the power comes out of neg side of battery and the alternator supplys it back threw pos terminal, thats why a good ground is a must, with a 1000w amp with 0guage power wire and a shit ground it would be like useing a 8guage wire for grounding if that helps
i tried to find a video of it on youtube but they must of taken it off or i dont know exact name for it
hope this helps
THANK U