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250-amp Big 3 wiring upgrade kit

Item # 122BIG3XP

California customers:
Please click here for your Proposition 65 warning.

Item # 122BIG3XP

In stock

Since 1974

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Installation help for your car, from our experts.

About the XS Power BIG3XP

The one-step "Big 3" upgrade kit

 If your aftermarket audio system is putting a strain on the rest of your car's electronics, you might want to upgrade your factory wiring. Rated to 250 amps, this "Big Three" grounding kit will boost your electrical system's performance.

XS Power's Big3XP kit includes heavy-duty 1/0-gauge copper-clad aluminum cables that replace (or augment) your vehicle's battery ground-to-chassis wire, the chassis-to-engine block wire, and the wire connecting the alternator's positive output to the battery's positive terminal.

Another bonus is that the 8.5 mm ring terminals are already crimped to the wires, so you won't have to replace the stock grounds unless you want to improve them or double up.  Extra ring connectors are included, so you'll be able to trim the wires to length and replace the terminals if needed.

The Package

This Big3XP kit includes: 

  • 1 6-foot XPFLEX 1/0-gauge power cable
  • 2 4-foot XPFLEX 1/0-gauge ground cables
  • 8 XS Power heat shrink tubes
  • 8 1/0-gauge crimp terminals (already crimped on the wires)
  • 10 wire clamps
  • 10 zip ties
  • 10 screws

Warranty: 1 year

Product Highlights:

  • MFR # BIG3XP

What's in the box:

  • One 6-foot XPFLEX 1/0-gauge power cable with ring terminals on both ends (blue)
  • Two 4-foot XPFLEX 1/0-gauge ground cables (black)
  • Two extra 1/0-gauge crimp-on ring terminals
  • 2 Heat shrink terminal protection tubes
  • 10 wire clamps
  • Ten 3" Zip-ties
  • Ten 1/2" Self-tapping screws
  • Instructions on the box

Customer reviews

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XS Power BIG3XP reviews

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More details on the XS Power BIG3XP

Mark G.

Product Research


Contents: The BIG3XP kit contains the following:

  • Power Wire: One 6' length of 1/0 gauge multi-strand power wire in a blue jacket (5250 strands/10% oxygen free). Both ends have ring terminals attached; 0.715" wide and 0.330" inner diameter.
  • Ground Wires: Two 4' lengths of 1/0 gauge multi-strand ground wires in black jackets (5250 strands/10% oxygen free). Both ends of each wire have ring terminals attached; 0.715" wide and 0.330" inner diameter.
  • Installation Accessories:
    • Two additional 1/0 AWG crimp-on ring terminals
    • Two heat shrink tubes (used with the extra ring terminals to protect exposed surface)
    • Ten wire clamps
    • Ten 1/2" Self-tapping screws
    • Ten 3" Wire ties

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Customer Q&A

11 questions already asked

Do I need to remove factory connections or can I just leave them as is and just add the Big3 cables?
[ Felix  Dec 28, 2018 ]
8 answers
I'm no expert, but as far as I know there is no problem with leaving the factory cables. However, you may run out of room on posts or you may not have room for the newer, thicker cables. These new cables are MUCH thicker than your existing, no matter what vehicle you drive.
[ Gary A.  Dec 31, 2018 ]
You can leave as is and just add the Big3 cables.
[ James  Dec 29, 2018 ]
Keep factory locations, electricity takes the path of least resistance and it's better to leave the factory connections for peace up mind.
[ Jacob  Dec 28, 2018 ]
I wouldnt remove any factory cables unless it interferes with installation of the big3 cables.
[ jon  Dec 28, 2018 ]
I just add the cable
[ stanley  Dec 28, 2018 ]
You can run them without removing the factory ones
[ Joseph  Dec 28, 2018 ]
Definitely leave them.
[ KEITH  Dec 28, 2018 ]
I just added mine to the existing wiring.
[ Gary  Dec 28, 2018 ]
Do I need this one or the more expensive one? I'm running 2 amps, one at 110x4 and another at 600x1.
[ Felix  Dec 24, 2018 ]
2 answers
From my personal experience, at a little over 1000 watts the big 3 is not necessary.
[ Ronnie  Dec 25, 2018 ]
That is perfect for your setup, your amps will thank you. Go on more step and add a extra battery.
[ Calvin  Dec 24, 2018 ]
This kit is 49.99 and you have another 99.99 they read the same output but the more price one is 100%OFC wire and cheap one is 10%OFC?
[ Joseph  Aug 21, 2018 ]
2 answers
Yes 100%ofc is pure copper which is corrosion resistant over the 10% it flows electricity alot faster,and cooler it's for high end electrical components and high power flow with very little drop of voltage and amps
[ ryan  Aug 29, 2018 ]
Get the $49.99 one. You'd be wasting your money for the $99.99 kit. The only time you'd need the $99.99 one is if you're running a lot more current through your wire. Like if you had a fully loaded system with bells whistles on your car and several amps and capacitors. In which case I'd upgrade my battery to a performance battery as well. Hope this helps Chive On!
[ Carson  Aug 29, 2018 ]
The big 3 usually seems to include alternator to battery positive, battery negative to ground, engine block to chassis ground (and that's what the product description describes), but the kit's directions say alternator to battery positive, battery negative to ground, and *alternator ground* to chassis ground rather than engine block to ground. Which would be best? Thanks, guys!
[ James  May 22, 2018 ]
2 answers
Engine block to ground is the better option. IMHO
[ Loumpy  May 22, 2018 ]
I'm not sure that either one is "better". I purchased this same kit and I installed it like this: 1) Alternator to battery positive 2) Battery negative to chassis ground 3) engine block to chassis ground ^^ I've never had issues with this install. I think some alternators can be/some people do ground to the chassis.
[ Erick  May 22, 2018 ]
Do I need to put a fuse on the charging cable from my alternator to battery? I have a 230 amp alternator.
[ Sal  Apr 01, 2018 ]
7 answers
your stock alternator cable has a fusible link , so yes you need to fuse the new alt to battery cable
[ brian  Aug 19, 2019 ]
230 amp alternator is nice to have. I've never personaly seen a fuse from your alternator to battery. But i guess it wouldn't hurt or be a problem unless your battery can't handle 230.
[ BRYAN JAMES  Apr 13, 2018 ]
You don't have to but I always do just to be safe. If you alternator goes bad your not going very far anyway...
[ Patrick  Apr 09, 2018 ]
[ Mitchell  Apr 09, 2018 ]
It's not necessary but will not hurt to do so hopes my answer helps u
[ GEORGE  Apr 09, 2018 ]
NO you don't have to put fuse. look for the video on you tube and get better idea. i hope this help you.
[ Carlos  Apr 09, 2018 ]
[ Zachary  Apr 08, 2018 ]
How would I crimp one end after cutting it to size? And do I need to cover the wires in loom or techflex?
[ James  Nov 10, 2017 ]
2 answers
With any crimp tool for the gauge of wire you have. Search for "Hydraulic Wire Battery Cable Crimper". You can find these on amazon for a decent price. You don't "need" to cover the wire, but don't think doing it would be bad.
[ Erick  Nov 10, 2017 ]
I bought a 0gauge crimp tool for 40 bucks but these wires have some decent length to it unless you want to shorten it. I just have my wires bare been that way for a while now but tech flex looks a lot better go for it
[ QJUAN  Nov 10, 2017 ]
Can you call will your wiring kit work on a 7-3 Powerstroke in a 1999 F250 will your battery cable kit work on a 1999 F250 with the 7-3 with dual batteries?
[ 1bad68  Feb 17, 2017 ]
1 answer
You will want to contact an Advisor by phone (1-800-324-9695) or online chat to discuss compatibility with your vehicle. They will be able to pull up your vehicle and see if this will integrate. If it does not, then they will also be able to discuss other options with you.
[ Kenny  Feb 18, 2017 ]  Staff
I'm trying to run a secondary battery from my trunk if I have enough gauge cable will this kit work to do the rest?
[ Channing  Feb 06, 2017 ]
1 answer
What do you mean do the rest do you already have wires ran to the back to connect the second battery let me know exactly what you are trying to do
[ QJUAN  Feb 06, 2017 ]
how to do the big 3 upgrade with a battery under the rear seat?
[ Tim  Jun 18, 2016 ]
1 answer
You have to run zero gauge wire from the battery the same way if it was under the hood. Gonna cost a lot more for sure.
[ ALAN  Jun 19, 2016 ]
On the answer to this question why do you say "The problem with doing the big three is the increase power flow to your alternator. " what problem are you talking about ,?why would there be a problem,? shouldn't it be a solution ?
[ Dawn  Dec 01, 2015 ]
1 answer
I believe Paul's concern there was about too much power going to alternator and causing an issue with it. I don't expect that would be a problem for most alternators.
[ Jeff  Dec 01, 2015 ]  Staff
OK so I just bought a capacitor and it didn't help my lights that were dimming at all? How much would this benefit and would I have to but a high output alternator? I don't want to spend much money and if the capacitor is a waste I'll take it back for refund. I'm running 2 10 in Alpine type s Subwoofers with a Alpine m-1000 amp.
[ Remington  Jan 09, 2014 ]
3 answers
This will allow more power to flow through your car. The wiring your car has now is very thin. The problem with doing the big three is the increase power flow to your alternator. Depending on how many amps your stock alternator is and how many watts rms you are going to be pushing will tell me more how important it is to replace your alternator
[ PAUL  Jan 09, 2014 ]
Lose the cap they usually don't help much. It's hard to say how much you'll benefit but you will benefit nonetheless. it depends on your alternator size and current wiring. The big 3 will more than a cap probably would.
[ Eugene  Jan 09, 2014 ]
Definitely get your money on the capacitor for the money you spend on a good capacitor you could by a good XS Power battery for under your hood and that would probably fix your light dimming problem. If you can afford to do the big 3 and replace your under the hood battery with the biggest Xs Power battery you can fit it will stop your dimming especially on a 1k amp. Hope this helps. Blessings!
[ Darius  Jan 09, 2014 ]

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