Grounding to battery or car

[pimpnyou204 10+ year member]

Just looking for a real quick anaswer basically. Ive heard different views from shops etc. But if you have a battery in the trunk 1/0 from front batt to back batt then 1/0 grounded from negative on battery. Now if you have 2 amps i was told to ground to what ever is the nearest and never ground further than 4 ft. Which is better grounding to negative on battery, to the spot on the car where the battery is grounded or to the car in a completely seperate spot?

Also if you ground to the battery with 1/0 wouldnt you need to add another another 1/0 from the battery to the ground so you have equal resistance?

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[groundpound4200 5,000+ posts]

I ground right to my batteries but they are grounded to the vehicle about 2 feet a way with 2 1/0 wires.

 

[CHEMMINS 10+ year member]

Back to the batt is always best.

 

[CHEMMINS 10+ year member]

Back to the batt is always best.

 

[pimpnyou204 10+ year member]

That is what I was thinking but if u have 2 1/0 runs to the battery negative u also have to have 2 more runs (2 from amps, 1 from front batt = 3) correct?

If you have 270 amp alt

370 amp sub

110 highs amp

This would require 3 right because a 1/0 can carry 300 amps?

 

---------- Post added at 07:08 PM ---------- Previous post was at 07:08 PM ----------

 

Also all 3 grounds from the battery can be grounded at 1 spot on the car?

 

[Bettr n' Revrse 5,000+ posts]

That is what I was thinking but if u have 2 1/0 runs to the battery negative u also have to have 2 more runs (2 from amps, 1 from front batt = 3) correct?
If you have 270 amp alt

370 amp sub

110 highs amp

This would require 3 right because a 1/0 can carry 300 amps?

 

---------- Post added at 07:08 PM ---------- Previous post was at 07:08 PM ----------

 

Also all 3 grounds from the battery can be grounded at 1 spot on the car?

What the hell are you running?!

 

[CHEMMINS 10+ year member]

You do understand that your battery is the ground......you are grounding everything to it.

 

[pimpnyou204 10+ year member]

You do understand that your battery is the ground......you are grounding everything to it.

I thought for a back battery you need to still ground it out?

 

[pimpnyou204 10+ year member]

You do understand that your battery is the ground......you are grounding everything to it.

I thought for a back battery you need to still ground it out?

 

[pimpnyou204 10+ year member]

What the hell are you running?!

I guess what im asking is how much wiring am i gonna need.

Dc 270 amp alt

AQ 3500d 370 amp draw

soundstream rubicon 4.600 120 amp draw

With that much draw i currently have..

2 1/0 + to back batt or is just 1 run good enough?

Then i could just run my amps - and + to the back batt as a distro

Now how many runs of - would i need from back battery to ground? Match my + runs to the battery currect?

 

[pimpnyou204 10+ year member]

What the hell are you running?!

I guess what im asking is how much wiring am i gonna need for...

Dc 270 amp alt

AQ 3500d 370 amp draw

soundstream rubicon 4.600 120 amp draw

With that much draw i currently have..

2 1/0 + to back batt or is just 1 run good enough?

Then i could just run my amps - and + to the back batt as a distro

Now how many runs of - would i need from back battery to ground? Match my + runs to the battery currect?

 

[Stryker 10+ year member]

If you can, just run 1 ground from back batt(s) to a mounting bolt on your alt.

might save you a couple feet of wire. I have a similar amp draw as you and only have a single run of 0Ga

very minor volt drop....like .2 -.4 which is nothing.

 

[wickedwitt 10+ year member]

I guess what im asking is how much wiring am i gonna need.
Dc 270 amp alt

AQ 3500d 370 amp draw

soundstream rubicon 4.600 120 amp draw

With that much draw i currently have..

2 1/0 + to back batt or is just 1 run good enough?

Then i could just run my amps - and + to the back batt as a distro

Now how many runs of - would i need from back battery to ground? Match my + runs to the battery currect?

Let's take the AQ3500- if and I do mean if you get 3500w out of it at 12v, that's 273A. That would be on a full draw for probably 40/1000s of a second on a perfect note. More realistically, between imp. rise, variance between notes, and having voltage that stays 13.5+: you would be looking more like a 222A draw maximum (giving the AQ a generous operating RMS of 3000w) and more like a constant draw of 100A. Between your two amps, the alternator itself should more than keep up with the current draw with 1 1/0 run from it straight to the back battery.

That said, it never hurts to have overkill. I wouldn't expect 370A draw out of anything less than an 8k amp, however. Not an operating draw at least.

.02

 

[reallyxxxxloud 10+ year member]

Let's take the AQ3500- if and I do mean if you get 3500w out of it at 12v, that's 273A. That would be on a full draw for probably 40/1000s of a second on a perfect note. More realistically, between imp. rise, variance between notes, and having voltage that stays 13.5+: you would be looking more like a 222A draw maximum (giving the AQ a generous operating RMS of 3000w) and more like a constant draw of 100A. Between your two amps, the alternator itself should more than keep up with the current draw with 1 1/0 run from it straight to the back battery.
That said, it never hurts to have overkill. I wouldn't expect 370A draw out of anything less than an 8k amp, however. Not an operating draw at least.

.02

Bingo

 

[Chriszle 10+ year member]

If you have a unibody car, you should ground battery to battery, but if you have a solid frame to ground to, it is perfectly fine to do that instead.