huge wiring upgrade

[TNTR70 10+ year member]

like i said, i'm upgrading all my wiring in my car and i have a quick question. i'm putting in three optima red tops. one battery in front and two more in the back. i plan on running two runs of 1/0 positive and one run of 1/0 negative to two red tops in the back of the car. the two runs of positive will be split one run to each battery in the back and then one 1/0 connecting those two in the back. the run of 1/0 for ground will go to the first one in the back and then jump to the second battery.

should i also ground the two batteries in the back to the chassis also. i planned on using the bolt that holds the rear seatbelt tensioner. i figure if its strong enough to hold a person in the seatbelt during an accident then there would be enough metal there for a good ground.

i'm taking pics of everything for a thread later on but don't have them right now

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[TNTR70 10+ year member]

bump..........screw it. i'm gona ground them to the chassis too...what could it hurt right?

 

[loopkiller 10+ year member]

Anytime you need 2 runs of POS+ wire, you need two runs of NEG- wire. Would you run 1/0 POS+ to your amp and then 8 gauge NEG- for your ground? NO! You always should use the same wire for the POS+ and the NEG-. Remember that DC electricity runs in a loop. Down the positive and back on the ground. Car grounds are not made to handle large electrical loads, therefore they have high resistance and you will have voltage drops because of it.

Also, on a side note. If you need multiple runs of 1/0, why not just run one run of bigger wire? It would probably be cheaper to run a single 4/0 than two 1/0 runs as well. I have seen 4/0 welding wire as low as $4.50/ft and is rated to 600A @ > 50ft runs.

Also the grounding in the rear will not hurt, but it likely will not help unless you have a ground wire failure. It is thought of as a good idea as a backup.

 

[schrummy 10+ year member]

wrong!!!!!

electrons go - to +

 

[loopkiller 10+ year member]

wrong!!!!!electrons go - to +

Wrong! Electrons are negatively charged, but they flow from the POS+ to NEG- in a DC circuit.