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Connectors XT-90

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    Connectors XT-90

    Product Link: XT-90 Connectors at

    The XT-90 connector is a 2 conductor keyed connector, meaning it can only be assembled one way preventing reverse polarity connections. It is rated for 90 amp duty ,designed to handle 90 Amps continuously without exceeding 80°C. XT-90 connectors consist of a male and female pair, the protruding connectors are on the male half and the recessed connectors are on the female half. The outer plastic shield does not affect the gender assignment of connectors.

    Luna products use this connector for the output current from their batteries, with the female connector being attached to the battery and the male connector attached to the controller. Luna sells only brand name XT series connectors, there are a lot inferior products in the marketplace so always buy from a trusted source to insure the performance is as designed.

    XT-90 connectors are available in 2 colors, yellow and black in addition to with or without attached pigtails.

    A variant of the XT-90 is the XT-90S , with the S designating spark suppression. It is highly recommended to use the spark suppression model on your primary battery connection. Connections made without this feature can arc upon attaching or detaching, leading to deterioration of the contacts over time.

    XT-90 connectors are available in various quantity packages and as part of adapter cables (i.e. XT-90 to Anderson power-pole) XT-90S connectors are available in yellow only.

    XT-90 solder lugs are ideally sized to accept 10 AWG wire , with silicone jacketed high strand count wire being the preferred type for this application. Click image for larger version  Name:	xtsizes.png Views:	2 Size:	481.0 KB ID:	8599Click image for larger version  Name:	xtcomparison.jpg Views:	1 Size:	260.6 KB ID:	33364
    Will a regular XT 90 work with an female XT 90 antispark?
    Yes it will. Only the female is antispark there is no such thing as a male antispark XT 90. The thing that makes the XT 90 antispark is resistors, these resistors only exist in the female part of the connector.

    So how does it work?
    The below pictures show a closeup of an XT90-S without the pigtails.

    Click image for larger version  Name:	XT90SAntiSparkConnector20.jpg Views:	959 Size:	39.4 KB ID:	55515
    The green is the resistor. This basically allows a small amount of electricity to come in so when you are plugging in halfway enough electricity is coming in so it does not spark when plugged in the rest of the way.

    Click image for larger version  Name:	Tdnwp6b.png Views:	965 Size:	76.8 KB ID:	55516

    Note: Do not leave the connector plugged in halfway, using high power while plugged in halfway will heat up and melt the resistor. While it may be enough to power on your system, you want to make sure

    This is plugged in partway where only the resistor is connecting
    Click image for larger version  Name:	XT90S--Anti--Blitz--1--Paar--Stecker--Buchse--90A_2.jpg Views:	934 Size:	21.9 KB ID:	55517

    This is plugged in all the way.
    Click image for larger version  Name:	XT90S--Anti--Blitz--1--Paar--Stecker--Buchse--90A_3.jpg Views:	984 Size:	21.4 KB ID:	55518
    Last edited by paxtana; 04-20-2017, 07:57 AM.

    For interoperation, if the XT90 is not fitting XT90-S this is likely because it is a knockoff rather than genuine Amass XT connector or an older XT90.

    I cannot speak for every XT seller on the market but with the XT90 connectors sold by Lunacycle they are compatible with XT90-S.

    See below for a demonstration


      Click image for larger version Name:	xtcomparison.jpg Views:	1 Size:	260.6 KB ID:	33364

      Note that this picture is of a XT60 connector. Used only to illustrate male and female ends...
      Last edited by Tommycat; 05-14-2018, 10:17 AM.
      See my completed Magic Pie V5 rear hub motor E-Bike build HERE.


        Every XT90S female I've gotten, online, local RC stores, wherever (I used plenty of the non-spark XT90's in my RC days and often just go the local RC store to get them even today - when planning a project I buy them online, ebay, etc.) was 100% compatible with the XT90 males. I've got dozens of the non-spark types and at least half a dozen XT90S's, I didn't worry about them in the RC's and once I got into the ebikes bought the XT90S's and they all were completely compatible. So that's my personal experience.

        I've not once seen someone prior to here say they are incompatible. That's the board experience.

        From an online buyer's perspective, every site selling them that states anything about compatibility also says they *are*.


        None of the discussion here dissuades me from my personal experience that there is *zero* difference between an XT90S and XT90 male.

        Last edited by AZguy; 05-07-2018, 07:25 AM. Reason: Limit the post to the compatability evidence after the debate posts were deleted


          I can confirm that it is possible to run across XT90 connectors that won't fit--as pointed out in the comment above the interconnecting video. That happened to me on an RC model someone asked me to upgrade. It might say XT90 on it, but it might be a "knockoff" part.

          I then made an ass of myself here, during my attempts at trying to figure out why they hadn't fit (and I've since deleted those errant diatribes).

          My experience suggests if you didn't install the old one yourself, so you don't know where it came from, it might be best to just go ahead and replace both sides brand-new.

          The price for the XT90-S set at Luna Cycle is extremely competitive, as anyone can see.

          But no matter where you buy them, these connectors are ultimately very inexpensive, when compared to the components they're there to protect, right?

          I'm not in the business of selling connectors, but I think if you're not sure, or your old ones are "sloppy", this could be one of those times it just doesn't "pay" to be cheap. In that case, just buy both.

          Take care,


          [edit--picture added--see comment below]

          Click image for larger version

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          Last edited by tklop; 08-21-2019, 04:11 AM. Reason: to add photo


          • tklop
            tklop commented
            Editing a comment
            There is a Big Brother to the XT90-S; the QS8-S.

            It may have been around for ages, but it's something I've only just discovered--and this thread seemed like the place to share it.

            The QS8-S is shown in the picture above alongside its XT90-S counterpart to show the size-difference (see above--at the bottom of the original reply). The QS8-S is rated for 180A.

            Conrad--the retailer I bought it from--lists the item as the RC120-S; and the two halves (male and female sides) are sold separately. Here's the link to the product where I bought it (Dutch language website):

            Uw Reely 1555055 Accupack bus RC120-S Verguld 1 stuk(s) koopt u bij Conrad Electronic. ✓ Altijd originele producten ✓ Gratis retourneren ✓ 30 dagen bedenktijd

            Uw Reely 1555056 Accupack stekker Verguld 1 stuk(s) koopt u bij Conrad Electronic. ✓ Altijd originele producten ✓ Gratis retourneren ✓ 30 dagen bedenktijd

            Performing your own internet search for QS8-S will likely yield more geographically relevant results--in terms of finding a retailer.

            For those with higher discharge-rates and heavier-amperage projects (besides just myself--I mean), this might be just the thing.

            As seen in the picture, the QS8-S is certainly bigger than the XT90-S is, but it's the same shape; same functionality. Plus, it's still much smaller than a similarly-rated 200A (light-blue) Anderson connector--which wouldn't have spark-suppression...

            I have no idea if Luna Cycle intends to stock this item or not--that's clearly not up to me. Of course, they've no shortage of power-junkies for customers--but the world of retail isn't only about need--it is also about space, and the turn-around of products (among other things). For all I know, this item might not move fast enough to justify stocking it.

            All the best, everybody!
            Last edited by tklop; 08-21-2019, 09:17 AM.

          Sorry if I came off as offensive, I cannot speak for the authenticity of XT connectors from other suppliers nor their interoperation.
          I can only say that with the Luna XT90 connectors, XT90-S connectors, and XT90 Pigtails connectors, and XT90-S Pigtails connectors, they all plug into eachother. See below for example.

          That's not to say there are not differences.
          Standard XT90 does have a larger plastic hole on female as seen in the below pic but has thicker metal so the inner diameter of the contact is essentially the same.

          Additionally the regular XT90 is a little shorter as you can see in the pics.
          This does not prevent interoperation but is perhaps notable as it may not look as pretty having them plugged into eachother.

          Click image for larger version  Name:	image.png Views:	1 Size:	578.1 KB ID:	64496Click image for larger version  Name:	image.png Views:	1 Size:	785.6 KB ID:	64497