Double 1/0 CCA vs Single 2/0 CCA vs Single 1/0 OFC

[UnknowingDIYer]

I know it has been rehashed over and over, but I am still having trouble deciding the best way to wire my new HO Alt with the rest of my planned system. I would greatly appreciate the experts to give this amateur some assistance.

Build for Jeep Wrangler Unlimited:
BNR Parts 350 Amp Alternator (Purchased) Yes... I know their reputation, but only the small shops have 300+ amp alts for the 3.8L jeeps.

Kenwood DMX9707S (Purchased)

Dual Skar VXF-15 D4 (Purchased) wired to 4 ohm at 3,000W RMS
Deaf Bounce Apocalypse AAB-7900.1D(Purchased) 4 ohm RMS 3000W

Alpine PDX-F6 (Purchased)
Hertz MLK 165.3 Pro (Purchased) 110 RMS Each Side in Knee Panel & Dash
Hertz ML 1650.3 (Purchased) 100W RMS Each in Roll Bar

XS Power 3100D (Purchased) 12V BCI Group 31 AGM Battery, Max Amps 5,000A, CA: 1565, Ah: 127, 4000W / 5000W+

Mosconi 8 To 12 Aerospace (Purchased) - I am looking for a controller, so message me if you selling one

Wiring - Plan on using 2/0 welding wire


My Questions:
What size wire should I use for the Big 3? In my head, I like two runs so that I can put 300amp fuses on the lines. If I run one line, I would have to run a fuse higher than the amps output and I heard running too high of fuses becomes less effective in managing heat/fires... or am I mistaken?

What size wire should I use for the line from the main battery under the hood to the rear batter? Again, I'm thinking of two lines so I can put 300amp fuses on them?

What size secondary battery should I use? I see people suggesting just adding up the RMS. So I'm thinking between the XS Power D4900, D6500, OR D3400R?

Edit: Updated after changing calculations from 2ohm to 4ohm
Edit2: Updated new build

Click to read more...

 

[2023 LTZ]

I’ll comment on a couple areas of your post. In the case you choose a single run and really either way you’ll want a fuse after you distribution block/s which are essentially a step down to fit your amps. This is if they don’t have onboard fuses already.
Pertaining to wire size, I am unaware of a benefit from having two runs. If your system was 10x bigger and you ran huge wire, the distribution block still reduces it down to fit your amp/s. The fused distribution block is their protection. If you had a 1000a fuse under the hood bc of your huge alternator this fuse allows the power back to be distributed. Extra or overhead power is dead ended or not made by the alternator bc demand isn’t there.
They make larger than 300 amp fuses.

Also on the wire sizing, I chose 4-0 from alternator to battery and 0ga after that. My idea was this way I have room for the alternator to also run vehicle accessories and the system wide open.

I posed a question several days ago regarding the second battery and it must not have been exciting or controversial enough for the majority to respond yet I’ll share this w you. Which ever wire you choose, have it go to your second battery then a separate run off the second battery to the distribution.

 

[Firewalker]

What year Wrangler with the 3.8? J&s has two different ones a 250 and a 320 amp both hairpin styles for 2007-2011. I would return that BNR and buy one of those. Especially considering the cost of 380 dollars for an ugh BNR alternator vs 439 for a quality one you know will last.

2007-2011 Jeep Wrangler High Output Alternator

Upgrade your 2007-2011 Jeep Wrangler Alternator with a JS high-output alternator. Ensure reliable power for all electronic components, even under heavy load. Durable & performance-tested. Shop now!

js-alternators.com

Also I would go with 1/0 OFC all day long regardless of the size or runs of the CCA.

 

[deez283 10+ year member]

I'd skip the car audio branded wire and get you some 2/0 welding wire.

 

[Firewalker]

I use nothing but welding wire. Always works great and is still flexible. But some 1/0 OFC kits are now around 100 bucks which include a bunch of stuff but he would still need extra 1/0 for the big 3.

 

[2023 LTZ]

I sourced welding wire and connections from amazon.
Windynation has good prices and is available by the foot. Fair prices on the terminals needed too.
It’s quality stuff. Made in a place called u sa.

 

[deez283 10+ year member]

I use nothing but welding wire. Always works great and is still flexible. But some 1/0 OFC kits are now around 100 bucks which include a bunch of stuff but he would still need extra 1/0 for the big 3.

What kits do you speak of?

alot of those "kits" come with junk anyway.. open ended lugs, rubber boots, cheap rca's

Can get copper closed end lugs, Glue lined heat shrink from the place you buy the welding cable and get some rca's from parts express for like 7.00

I feel like I could put together a better kit for 100.00 than I would get going "branded" kits.

 

[dragon.breath 10+ year member]

First, two d4 subs can’t be wired at 2 ohms. Your options are 1, 4 or 16 ohms.
Second, the 214 amp figure is not correct. That would require the amplifier to be 100% efficient. Which is not possible. A true 3000 watt rms burp would draw around 300 amps.

 

[UnknowingDIYer]

What year Wrangler with the 3.8? J&s has two different ones a 250 and a 320 amp both hairpin styles for 2007-2011. I would return that BNR and buy one of those. Especially considering the cost of 380 dollars for an ugh BNR alternator vs 439 for a quality one you know will last.

2007-2011 Jeep Wrangler High Output Alternator

Upgrade your 2007-2011 Jeep Wrangler Alternator with a JS high-output alternator. Ensure reliable power for all electronic components, even under heavy load. Durable & performance-tested. Shop now!

js-alternators.com

Also I would go with 1/0 OFC all day long regardless of the size or runs of the CCA.

JS is ran out of a guy's backyard in SC, maybe he got a shop the past year, but in my eyes JS and BNR Parts are both crap, but all I have in terms of options for 300+ amps.

 

[UnknowingDIYer]

First, two d4 subs can’t be wired at 2 ohms. Your options are 1, 4 or 16 ohms.
Second, the 214 amp figure is not correct. That would require the amplifier to be 100% efficient. Which is not possible. A true 3000 watt rms burp would draw around 300 amps.

You are correct about the 2ohms not being possible. I wonder why my multimeter was saying it was wired at 2 ohms. I'll have to pull them out of the box and see how they are wired. I tested the resistance at the box's terminals and it said 1.9 ohms.

My 214 figure is correct as I subsequently stated I need more to account for inefficiency.

Edit: Just went out and retested the subs and you're correct. Resistance showed 3.5ohms so they are wired to 4ohm.

 

[UnknowingDIYer]

I sourced welding wire and connections from amazon.
Windynation has good prices and is available by the foot. Fair prices on the terminals needed too.
It’s quality stuff. Made in a place called u sa.

Can you give me a link to what you bought exactly and which terminals you used? I heard welding wire is good, but I also heard it gets tricky matching welding wire gauge to terminals since they run smaller than normal audio wire.

 

[deez283 10+ year member]

Can you give me a link to what you bought exactly and which terminals you used? I heard welding wire is good, but I also heard it gets tricky matching welding wire gauge to terminals since they run smaller than normal audio wire.

You can get temco 2/0 for 4.00 a ft shipped on Ebay.. I'm sure you can find some cheaper if you searched around.

How do you plan on crimping this stuff?

You can get the Wire, Lugs, heat shrink, and Hammer crimper all from temco..

Welding 2/0 is equal to oversized car audio 1/0 like skyhigh.. but it weighs slightly more.

 

[2023 LTZ]

If you have amazon type in windynation 1/0 ga. Its the first thing that comes up, black or red, 10 terminals and quality heat shrink.
I find that they’re also small but if the ends are perfect and you really work it, it does fit.
I don’t usually endorse amazon but this deal is good.

 

[UnknowingDIYer]

You can get temco 2/0 for 4.00 a ft shipped on Ebay.. I'm sure you can find some cheaper if you searched around.

How do you plan on crimping this stuff?

You can get the Wire, Lugs, heat shrink, and Hammer crimper all from temco..

Welding 2/0 is equal to oversized car audio 1/0 like skyhigh.. but it weighs slightly more.

I was going to use a hydraulic crimper from amazon for like $70.

Amazon product ASIN B09Y5ZJTZ3

 

[2023 LTZ]

I bought a hammer one from northern for $20. I’d imagine harbor freight or other discount tool places have a variant of that too. Ive crimped several 4/0 connections w out problems.