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Anyone know of a capacity tester that will discharge a 52v battery at around 500w?

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    #16
    I'm not surprised by the different values at different loads, the cells have a "sweet" spot. It's possible the BMS contributes but I would expect a BMS inefficiency to show up as worse at higher loads, but I suppose you never know - I suspect what you are mostly seeing is that cell sweet spot tho

    Yup, they should be consistent when tested at the same loads =] Temperature will make a difference tho

    When I looked closer at the pack pictures I realized it wasn't the same pack I've got (there's no switch on mine - makes some sense they might be 5p but if so that's pretty crappy Ah and is closer to what would be expected from more like 4p, at least with quality cells. Out of curiosity what's the pack weigh?

    Some of that chinese stuff is absolute crap. Big caveat emptor!

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    • Steve--
      Steve-- commented
      Editing a comment
      They weigh 7lbs, 2oz.

      And yeah, you're right about them being 4P. I just discovered that the original one I bought is having an issue with the BMS cutting it off too soon, at around 44v - 46v If I remember right. So I took it apart to see what size replacement BMS I'll need to order, and while doing so I counted the cells. They didn't have the configuration listed on their ad (and that's probably why), but I asked them what it was before I bought it and the person I talked to told me 5P, so I naturally believed them. Just more of their deception I guess!

      And although I know it's not necessary for a 1,500w pack, the fact that these ones are, also led me to believe they were 5P.

      Regarding the switch, it may still be the same pack, only they have started adding the switches the newer ones.
      Last edited by Steve--; 07-28-2021, 05:54 AM.

    • AZguy
      AZguy commented
      Editing a comment
      My 14s8p doesn't have a case and is just shrink wrapped and weighs just about right on at 6.5kg - since that's 112 cells and if we say the BMS, shrink and conductors weighs about 2 cells (rough guess for rough numbers) that yields pretty much 57g/cell (good enough for the rough stuff here!)

      14s4p should weigh the case, BMS and conductors + 56 x 57g (3.13kg or 6lb 15oz) so that makes perfect sense and frankly that's a good thing since if you had a 5p pack those would be pretty crappy cells to only give you 10Ah!

      My 14s4p in the similar case (it looks like the same plate) weighs a bit more than 3.2kg so right about where you are

      Frankly I think you got a good deal ;-} My similar cased 14s4p was twice that cost although I get ~12Ah from it...

    #17
    It would be interesting to see exactly what the configuration is. 14s5p with 2500mah cells would be 12.5ah and 4p would be 10ah. I really wouldn't expect cells any higher than 2500mah so it has to be at least 5p.

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    • Steve--
      Steve-- commented
      Editing a comment
      I guess they are 4P. I just discovered that the original one I bought is having an issue with the BMS cutting it off too soon, at around 44v - 46v If I remember right. So I took it apart to see what size replacement BMS I'll need to order, and while doing so I counted the cells. They didn't have the configuration listed on their ad (and that's probably why), but I asked them what it was before I bought it and the person I talked to told me 5P, so I naturally believed them. Just more of their deception I guess!

      And although I know it's not necessary for a 1,500w pack, the fact that these ones are, also led me to believe they were 5P.
      Last edited by Steve--; 07-28-2021, 05:53 AM.

    #18
    A peek inside!

    Click image for larger version

Name:	PXL_20210728_140324128.jpg
Views:	79
Size:	2.06 MB
ID:	133030

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      #19
      Final Testing Results

      ROUND 1__________________ROUND 2 ____________
      |
      BATTERY (A) BATTERY (A)
      Test #1. @ 7.1A Draw = 10.96Ah-------Test #1. @ 7.1A Draw = 10.88Ah
      Test #2. @ 2.0A Draw = 10.55Ah-------Test #2. @ 2.0A Draw = 10.75Ah
      ---------------------------------------------------------------------------------------
      BATTERY (B) | BATTERY (B)
      Test #1. @ 7.1A Draw = 10.76Ah-------Test #1. @ 7.1A Draw = 10.77Ah
      Test #2. @ 2.0A Draw = 10.32Ah-------Test #2. @ 2.0A Draw = 10.65Ah
      Last edited by Steve--; 08-03-2021, 11:22 AM.

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        #20
        Just a quick update!!!

        My free battery accumulation is up to 8 now. I've received 10 batteries so far in total, and have been completely refunded on 8 of of them (Still being allowed to keep them) while the refund process on the remaining two is still pending. I also ordered 6 more of them, which have already been shipped and are currently in transit.

        All of the first ones I ordered were 52v, but all the most recent ones are 48v, which were also advertised at 20Ah's. I've tested them as well, and they test pretty consistently at around 12.5Ah's.. All though I'm focusing on the scammers here, there are actually some honorable sellers on ebay advertising these batteries at a more honest 13Ah's. Even though that's SLIGHTLY higher than what they actually test at, I find advertising them at 13 pretty reasonable and don't have any problem with it.

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          #21
          Are you making any more comparisons like say size and weight? Curious if many are just using cells that are not nearly up to their claimed ratings or if some are using the sand filled cell trick or what.

          Comment


          • Steve--
            Steve-- commented
            Editing a comment
            Without the base they're right about at 7lbs, 1.6oz for the 52 volters, and right about at 8lbs, 5.1oz for the 48 volters. The 48v's are heavier because they're configured as 13 x 5 (65 cells), while the 52's are only configured at 14 x 4 (56 cells, Nine less than the 48 volters). Since the cases are identical, simple math would tell us that the individual cells weight approximately 2.166oz each.
            Last edited by Steve--; 09-12-2021, 05:32 PM.

          #22
          Another quick update. Well... It looks like they're beginning to fight back. They have now sent me return shipping labels for the two most recent 48 volters I received. They've apparently arranged for them to be shipped to another location here in the states since the destination address is in Lithia Springs Georgia (But as I mentioned before, the free batteries aren't my motivation for doing this, so this isn't going to deter me. Upon receiving the return shipping labels, I immediately ordered another battery from that same seller and intend to order a second one from them in a couple of days). And I intend to keep doing this with all the sellers, forcing them to pay for return shipping as long as I can.

          They're utilizing tactics to avoid paying the return shipping though too. I just checked on one of the pending orders I have, and the tracking number shows that my order that was supposed to be delivered here in Oregon, just got delivered to a location in El Paso Texas. I've reported this to ebay as a "not delivered" claim, and at the end of that process when I was presented with the two options "Refund" or "Reorder item," I chose the option to reorder the item, so we'll see how it plays out.

          I've talked a few of my friends into doing this as well, but I wish I could get a few more of you people out there to do it as well. The more people doing it, the quicker we can shut them down. I may not be able to accomplish it on my own. In fact, now that these sellers are getting to know me, it may not work for me at all any more. If there are any other people out there who are fed up with this type of fraud, please join me in this endeavor, and post updates here.

          P.S. I'm also in the process of putting together a YouTube series on this in hopes of encouraging more people to get involved. It's risk free.
          Last edited by Steve--; 09-12-2021, 05:48 PM.

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          • AZguy
            AZguy commented
            Editing a comment
            I suspect they are worse than cockroaches - squash one and three more appear and the one you thought you squashed just shows up somewhere else

          • Steve--
            Steve-- commented
            Editing a comment
            I'm beginning to suspect that as well, but I'll keep trying as long as I feel there's at least some possibility of making a difference. Even though they're getting familiar with me, it does see to still be working (with some sellers at least) with buyers they're not familiar with, as a buddy of mine ordered 4 48 volters, two each from two different sellers, and is getting to keep two of them from one one of the sellers for free (The other sellers sent return shipping labels).

          • MemberOfDistinction
            MemberOfDistinction commented
            Editing a comment
            I think it's possible they read these forums.

          #23
          Up to 10 free batteries now. That's $2,500 worth of batteries for free.

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