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News - BtrPower Battery failure after 20 uses - Seller says they sent replacement

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    News - BtrPower Battery failure after 20 uses - Seller says they sent replacement

    Hello,
    Back in June I bought a BtrPower 20Ah battery on ebay for $320.00

    It's been about 7 months and I've used it about 20 times.
    During that time it has been meticulously maintained at 76F inside and kept at storage voltage when not in use.
    The battery has never been dropped or abused on ANY way. In fact, it has had a gentle, cared for life so far.

    It has at least one dead cell (maybe more) and or the BMS has failed..
    Capacity had dropped to 8.13 Ah.

    It supposedly has a 1 year warranty and I have contacted the vendor on ebay.

    Let's see if they respond.

    Click image for larger version  Name:	48vbattery_1024x1024.jpg?v=1620896001.jpg Views:	0 Size:	90.5 KB ID:	146382
    MemberOfDistinction
    Guru
    Last edited by MemberOfDistinction; 1 week ago.

    #2
    That's pretty cheap for 20ah so there had to be some corners cut somewhere. Could be low quality cells or could be low quality construction so maybe you just have a cell or two that has become disconnected. BMS's are not that expensive so that isn't where they saved a lot of money but even a decent BMS can fail. Hopefully they will come through with some warranty.

    Comment


      #3
      How much does a lithium ion battery cost per kWh?

      Lithium-ion battery pack prices averaged $132 per kwh in 2021—down from $140 per kwh in 2020—and $101 per kwh on a cell basis, the report said. However, higher raw material prices are already pushing prices back up, according to the report, which predicted a $135 kwh average pack price for 2022.Dec 1, 2021

      $320 for 20Ah seems close to par to me.

      I have a 120Ah (1448 Wh / 1.45 kWh) LiFePO4 that I use for backup energy to power my camping vehicle when I travel. It was only about $50 more than the ebike battery. I'm becoming of the knowledge that building your own battery pack is better because you actually know what's going in it.


      MemberOfDistinction
      Guru
      Last edited by MemberOfDistinction; 1 week ago.

      Comment


        #4
        Quality raw cells may cost that much but raw cells don't make for a finished pack fit for an e bike. If you look at the cost of what are generally considered the good e bike packs they are about twice the one you mentioned even in 2020, I'm kinda afraid to look at today's prices. The lack of a hard case and mounting system explains part of the cost difference but not all of it. There could also be a difference in the profit margins but with how popular and competitive the aftermarket and kit e bike industry is I don't think that explains it all either so there has to be some other place they did some cost cutting.

        Besides cell quality the next biggest failure point for something like an E bike pack that gets rattled around is how its physically constructed and protected. You can make a pack work with cheap thin nickel plated steel strips poorly welded to the cells. You can then hold it all together with tape till you put the shrink wrap on and call it done. If you build a pack like that yourself and set it on a shelf it may work reasonably well. Ship that around the world then toss that in a bag on a bike where it can rattle and bang around its not going to last long before you end up with connection problems.

        Middle ground is glue or glued into some sort of framework then lots of shrink wrap or a hard case. The other extreme would be like Luna Wolves where its fully epoxy potted in a hard case. Fully potted nothing is going to move. All that stuff is material and labor cost on top of what the cells cost and it can add up and often explain some cost differences.

        Comment


          #5
          Originally posted by MemberOfDistinction View Post
          How much does a lithium ion battery cost per kWh?

          Lithium-ion battery pack prices averaged $132 per kwh in 2021—down from $140 per kwh in 2020—and $101 per kwh on a cell basis, the report said. However, higher raw material prices are already pushing prices back up, according to the report, which predicted a $135 kwh average pack price for 2022.Dec 1, 2021

          $320 for 20Ah seems close to par to me.

          I have a 120Ah (1448 Wh / 1.45 kWh) LiFePO4 that I use for backup energy to power my camping vehicle when I travel. It was only about $50 more than the ebike battery. I'm becoming of the knowledge that building your own battery pack is better because you actually know what's going in it.

          There's just no way the cells most commonly used in electric bikes (definitely not LiFePO4 this is far from common due to the much greater weight and size) are running even close to $130-$140/kWh

          I keep an eye on these cells and right now $400/kWh is going to be much closer for these cells (mostly LiNiMnCoO2 and LiNiCoAlO2 but some others too)

          For these popular bike chemistries a 20Ah/52V battery is going to run probably not less than $800 and if someone pays less IMO they either got scammed, a crap battery or very lucky, - but very unlikely the latter...

          Unless you are building at least several batteries it's not likely to make good economic sense when you look at the net cost including tool amortization, materials and labor (I for one don't value my time at $1/hr! Click image for larger version  Name:	wink.gif Views:	0 Size:	439 Bytes ID:	146411)

          Comment


            #6
            Figures.....
            Just about the time I "get into" a hobby........the cost goes into high orbit.

            $800 for a 20Ah battery makes no sense for a bicycle. NONE.
            For that money I could get a 200Ah LiFePO4 batteries to power my RV.

            If that's what it takes.....I'm out. 1000watt ebike Kit for sale
            MemberOfDistinction
            Guru
            Last edited by MemberOfDistinction; 1 week ago.

            Comment


            • AZguy
              AZguy
              Giga Member
              AZguy commented
              Editing a comment
              For the quality, light, small, energy dense and reasonably safe cells that are preferred for electric bikes that's the kinds of costs we are talking about and comparing an RV battery to something for an electric bike isn't even apple and oranges although retrorocket just mentioned in another thread he got a screaming deal on a 1kWh using 21700's for $650

              The chemistries commonly used in electric bikes are the same as what's used in most electric cars and electric motos... those aren't using using LiFePO4 for the same reason they aren't common in electric bikes... in an RV they make sense since they are safe, economical (for Li-ion), can be charged from systems setup for lead-acid and weight and size are far less of concern...

              The per cell costs have come down a little but not much - the capacities have been going up a little bit so overall the cost per joule is going down

              If weight isn't an issue just go lead-acid flooded cells or something to save money, lot less cost there... some guys have done LiPo too and while light weight they aren't all that safe particularly for how much capacity electric bike batteries require


              Bottom line there's no free lunch

            #7
            The ebay seller that won't respond to inquiries after the return period is over is.......

            iMotorBattery

            Comment


            #8
            Do you know what the cost of an $800 high quality ebike battery bought inside China is?

            I hear it is under $100 US.

            Comment


            • AZguy
              AZguy
              Giga Member
              AZguy commented
              Editing a comment
              I deal directly with chinese on a daily basis, have spent time there, so far from clueless

              Point about blue lasers is don't believe all the stuff people post on the internet, especially if they get ruffled when asked for sources

            • MemberOfDistinction
              MemberOfDistinction
              Guru
              MemberOfDistinction commented
              Editing a comment
              Sure you do....sure you have.
              Post the evidence

              Your blue lasers from space....I don't believe the stuff either.
              MemberOfDistinction
              Guru
              Last edited by MemberOfDistinction; 6 days ago.

            • AZguy
              AZguy
              Giga Member
              AZguy commented
              Editing a comment
              It's a big part of my business dealing with china - and it's just that - *my* business... I'm not making wild claims like things are orders of magnitudes less over there

              Frankly some things are.. A plate of food can be silly cheap...

              But I'm skeptical that similar size/quality batteries are that much less... they're going to be 20% less just 'cus of tarriffs and likely another 20% for shipping and maybe a little more for customs, etc.... but that's closer to half at best.. and what difference does it make? We're stuck purchasing them here...

            #9
            Back on topic........for anyone considering BtrPower.

            Heard from the ebay seller today. There was a delay of them getting back to me they say they were out of stock.
            In any event, the seller has promised they'd ship me a replacement and gave me a tracking number. This is at least a big positive step forward.
            Unfortunately, the battery is coming from China and may take some time to arrive. When it does, I'll post an update.

            IF.......

            The replacement works well then I'll retract my previous opinions.
            ANY battery or BMS can fail. What matters is the supplier keeping their promise of a warranty in case of a problem.
            If all goes well and the new battery works well, I will be able to recommend BtrPower again.

            Comment


              #10
              Ya let us know how it goes. Coming from China will be interesting to see how long that takes. Hopefully your replacement is already in route.

              Comment


                #11
                Sincerely hope it works out - I'd be braced for disappointment but sounds like you might be taken care of...

                Comment


                  #12

                  General Discussions
                  Talk about E-bikes, other hobbies and stuff you do for fun.
                  If you`re not sure where else to post. post it here.

                  Talk about E-Bikes and other stuff I/we do. Post it here

                  AZguy commented
                  I deal directly with Chinese on a daily basis, have spent time there, so far from clueless.

                  I enjoy this E-Bike forum and subscribe thru various topics.
                  I see AZ-guy giga member in a lot of E-bike topics. (Thank you for your service!)
                  I own a 2000 Chinese Surron X Light Bee, 2 other ICE dirt bikes and 1 pedal mountain bike.
                  This SRX-LB is great, but it`s turning into a money pit to improve it for serious dirt bike riding.
                  To compete in the Super-Senior Enduro class (70) I figure I need another $3500+ to improve the
                  suspension, battery, Controller, wheels, better everything that`s stock.
                  I see AZguy in the ""Commercial bikes"" forum and would like to get his opinion on the Kolter Banshee.
                  I can order one for about $7000.00 which might be cheaper than upgrading my SRX-LB.
                  Dealing directly with the Chinese. Are they going to be around for the future?

                  You seem like an honest guy. Whom would you recommend we deal with.?

                  PS: You are not obligated to answer any of this.

                  Comment


                  • AZguy
                    AZguy
                    Giga Member
                    AZguy commented
                    Editing a comment
                    I'd be happy to answer but honestly don't know ;-}

                    These days my dealings with chinese are mostly for electronic engineering and manufacturing... things are really grim with them these days, they are constantly shutting things down and if you all think supply chain is a problem, in this industry it is a complete nightmare. 90% of semiconductors are unibtainium
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