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250-amp Big 3 wiring upgrade kit

18 Reviews | 5 questions - 7 answers

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Our take on 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

The wires came clamped and everything ready to put on. Great Kit!

Laz, Naples, FL

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

Product Highlights:


    XS Power BIG3XP Reviews

    Average Customer Review(s):

    (18 Reviews)

    Great Kit

    Laz from Naples, FL on 11/13/2016

    Crutchfield Customer Review (What's this?)

    The wires came clamped and everything ready to put on. Great Kit!

    Pros: Wires Clamps Zip Ties

    Cons: Nothing

    Big 3 Power Cables

    Jaymie from Bronx, NY on 9/29/2016

    Crutchfield Customer Review (What's this?)

    These are quality cables, they're just the right length for my application. This kit comes with most accessories you need for an install except a cutter & crimp tools. Would recommend this for someone who upgraded their car stereo.

    Pros: Great quality, most accessories included for install. Good looks.

    Cons: None

    Xs big three upgrade kit

    Anonymous from Livonia, Mi on 7/27/2016

    Crutchfield Customer Review (What's this?)

    Very easy to work with the 1/0 gauge wire and it come pre crimped which is nice. Had to cut the power wire since my cars engine bay required only 2 ft from the battery to the alternator but with the right tools it's a breeze. All around great product for the money.


    Cons: None

    XS Power Big3XP review

    Jeremiah C from Lake Charles, LA on 7/26/2016

    Crutchfield Customer Review (What's this?)

    This item shipped directly from the manufacturer and Crutchfield had no communication as to whether it had shipped or not. I called XS Power and they didn't know about it but said they would call me right back. The next day I called them to get a status and XS Power stated that it was shipping from another warehouse and they were waiting on confirmation. It was finally shipped and arrived a few days later. Everyone I spoke with was very cordial. The product itself was exactly what I needed. The only problem is it cut out my sensor for battery fault. No big deal. I would recommend this product.

    Pros: Large enough gauge wire to not hinder a large alternator, easy to install after you chase down existing charging cables.

    Cons: Not really any Cons per say, could have come with a battery terminal and a way to connect sensor.

    Bad @$$ 1/0 gauge wire

    Tater from Southgate on 7/26/2016

    Crutchfield Customer Review (What's this?)

    This is a great deal??I mean it was well set up with alot of extras.Thanks again Crutchfield for coming through with a great product and even better service!!

    Pros: Everything about it!!!

    Cons: None


    lumpy from Sunland, CA on 7/20/2016

    Crutchfield Customer Review (What's this?)

    great kit for setting up your vehicles electrical system. the wire is easy to mold and run and with the extra ring terminals (you must have your own crimper) can make a really clean install.

    Pros: plenty of wire, extra ring terminals and heat shrink.

    Cons: could use a bit larger tie-wraps.

    XS Power BIG3XP

    Donald from Rochester, NY on 5/21/2016

    Crutchfield Customer Review (What's this?)

    Very High Quality Wire. Ends already crimped on. The Ground wires in Toyota are Crap. Just upgrading the ground wires has made the electrical system 95% better.

    Pros: High Quality Wire.

    Cons: The Power wire from Alternator to battery not long enough to go around the front of the radiator to the battery. This is how the stock wire is routed. Just have to route it differently.

    Great Wires

    Weifan W. from Virginia on 7/4/2015

    Crutchfield Customer Review (What's this?)

    The wires are quality. They were really flexible so installing it made it really easy on my 2012 Mazda 3. The 2 Ground cables were really long for me though so I had to cut one of them in half but that's not a complaint. It left me plenty of spare wires if I decide to ground other things in the engine. Overall if I had to buy it again I would.

    Pros: Long Wires, Quality build, and Easy Install

    Cons: None

    nice product

    kmack24 from the Washington, DC Area on 4/9/2015

    Crutchfield Customer Review (What's this?)

    Nice product, does the job that's all I could ask for :)



    big 3

    jeremy52 from panama city beach florida on 3/2/2015

    Crutchfield Customer Review (What's this?)

    I would give it 5 stars but I have not hooked it up yet. Just looking at it I am happy with the quality. I was hoping the connections would be soldered but they are clamped great either way. I was also worried about cable lengths but getting it I have realized the cables are plenty long. I may change a ground out to be the power so my final ground can reach my frame.

    Pros: Very strong connections for being clamped, definetly true gauge wire and it comes with plenty of cables.

    Cons: Connections clamped and not soldered.

    XS Power BIG3XP

    Anonymous from Akron, OH on 11/15/2014

    Crutchfield Customer Review (What's this?)

    Quality stuff worth the money



    Good quality

    JimmyB from Minnesota on 10/28/2014

    Crutchfield Customer Review (What's this?)

    I haven't installed the kit yet but it all looks like very good quality. I'm sure it will work great. Thank you.



    Big 3 Wiring Kit

    C from Foristell MO on 7/17/2014

    Crutchfield Customer Review (What's this?)

    I have a 1,200 watt amp running two Kicker Comp R's in my 2003 Accord. I realized that my amp was drawing too much power from my car and I had a slight fear that my alternator might go out. So I purchased this wiring kit which is 0 gauge wire. Easy install. Now I'm able to turn my gain up a little more and don't have to dealneith dimming lights. I recommend this product.

    Pros: Easy install.

    Cons: None

    Great Product

    BenD from Indianapolis, IN on 5/5/2014

    Crutchfield Customer Review (What's this?)

    This product took longer than expected to install just because of my vehicle type, Jeep, but once on, it works great.

    Pros: Ease of use, Price, Works great


    Very good, but I had to make adjustments

    Anonymous from St Amant, Louisiana on 4/23/2014

    Crutchfield Customer Review (What's this?)

    Everything was great the only thing I had to so was use the longer power wire as my alternator ground to be able to run the wire in the same place as the factory. And I just used the ground that was too short as the power wire. Other than that great overall.

    Pros: It helped provide plenty more power to my car!

    Cons: Had to switch out the power and ground wire. Worked good still.

    Good Product

    Bob G from Palm Bay, FL on 4/12/2014

    Crutchfield Customer Review (What's this?)

    Nice large gauge wire, no filler insulation, it's a true 1/0 gauge. Quite flexible given it's size. Installed it in my 1983 Camaro and the amount in this kit is enough to do the Big 3 three times over on my car. I literally have about 6' of cable left over, which is a great value in my opinion. This kit also helped out with some electrical issues my car had. The tiny little factory ground and charging wire wasnt big enough and as a result, my volt meter in the car would fluctuate each time my turn signal flashed. Turn on the headlights and A/C and watch the voltage drop well below 13v. Not anymore. I can crank up the stereo (with 250w amp), all the lights and the A/C on max and the voltage doesnt move. This kit certainly does it's job.

    Pros: Tons of wire with pre-crimped ends. Great Value

    Cons: Needs to be cut to length and new ends either soldered on or crimped which could be difficult for someone without proper tools.

    Great Kit

    Wader935 from Albuquerque, New Mexico on 12/1/2013

    Crutchfield Customer Review (What's this?)

    Everything you need for the Big 3 upgrade. I had plenty of cable for my installation and had about a foot left over. Very flexible 0 guage easy to maneuver around and through tight places. One end of cable is already crimped with a ring terminal and shrink-wrapped so installation was a breeze. Although not soldered just crimped, i was skeptical if it would hold but it did. I did a pull test and crimped ring terminal did not budge. The cable is very thick and i really had to work to get it into my 0 guage battery terminal, and if you have the right wire cutters its easy to cut. Kit comes with extra ring terminals, shrink wrap and even zip ties to make the install look nice and clean. Overall i am very happy with this purchase and would definitely recommend this kit to anyone doing their own Big 3 upgrade. Thanks XS power and Crutchfield for the great price.

    Pros: One end of each cable has a ring terminal already crimped and shrink wrapped.

    Cons: Cable was difficult to get into my 0 guage battery terminal, but the bigger the better for this instance. I did get it to fit so not really a con just a pain.

    high quality

    Hameen from San Diego on 11/25/2013

    Crutchfield Customer Review (What's this?)

    needed some wires for my high output Alternator 220amp this kit is rated at 250amp so it was perfect had all the correct tools to alter the size and mimic factory length. I would however suggest soldering the crimped wire before shrink rapping. great upgrade for your sound system.

    Pros: everything is included and this is a very good price for what you get. The only way to get it cheaper is to build the kit yourself

    Cons: not rated higher then 250


    Hands-on research

    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

    Our Product Research Team

    At Crutchfield, you'll get detailed, accurate information that's hard to find elsewhere. That's because we have our own in-house Product Research team. They verify what’s in the box, check the owner's manual, and record dimensions, features and specs. We stay on top of new products and technologies to help people make informed choices.

    Q & A

    Customer Q&A

    Crutchfield asked  
    Why did you buy this?

    quality company [ M  Dec 03, 2015 ]

    5 questions already asked

    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
    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 ]
    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 ]
    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
    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 ]