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Luna 52v 12ah Samsung pack issues

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    Luna 52v 12ah Samsung pack issues

    I bought this pack in Mar, 2020, it has 1800 miles and I'm not sure how many charges on it. Recently, it has been dying in the middle of a ride when there is still plenty of charge left. Previously, I had been able to get 60+ miles out of it on a setting of 2, but now it dies with no warning when there is still approx 60% left on the display. I charge it to 80% charge using the 52v 3amp Luna Mini Charger. My most recent ride, I tried to get it to die by running it at 500 watts pedal assist, and it lasted just under 6 miles, up and down some pretty good hills. What do you suggest I do about this?

    60% on the display and the display stays on? How do you get it going again?


    The having to be charged part implies its the BMS in the battery that is shutting things down. I think the shark packs can be taken apart and possibly repaired by someone who has experience repairing packs. Someone would have to take it apart and do some testing to determine if there is a problem with a cell or connection to a cell that is causing the BMS to cut things off or of the BMS is just failing.


      What 73Eldo said. Working through a similar 'cut out' issue on my X1 48V pack. It has been cutting out / going completely and instantly dead at higher and higher % charge levels since December 2020. Finally cut out/died at 76% one day and won't come back on. Looks like it is a dead BMS.

      Any type of warrant exchange/repair would be ideal. If that isn't possible or out of warranty - if you're electronically inclined, you can likely tear down, check things out and rebuild with a new BMS. Otherwise, some sort of bike/battery repair shop would be in order, or lastly, sell as non-functional and buy new.


        I'm having similar issues with my 52v Samsung 30q 12ah battery. I have ludicrus mode. I used to ride it to my office 24 miles away, but I just tried it out on Saturday and only got 17 miles. The bike has about 1100 miles on it. I was told that if you disconnect ludicrous mode then that will prolong the battery. I'm not sure how to do that and I'd prefer not to do it b/c I like the use of my throttle when I'm on surface street at stop lights. Any suggestions? I'm in LA (southbay) so if there's a local person who knows Luna bikes then I can take it to them, if needed. The main reason I bought the bike was for commuting so it's not much good to me if I can't get to the office.


          Does your display show the voltage? If so did you notice where it was at and how much it was sagging when it cuts out? That may give some clues to what is going on.

          Does your charger have % settings or does it always go to 100? If you have settings and don't normally go to 100 have you tried a few cycles in a row to 100% to let the cells balance?


            The symptoms listed by the OP are VERY similar to mine:


            I suspect a weak or bad cell or “parallel group” .

            The overall pack voltage is displayed on the controller and is watched by it’s Low Voltage Cut Off, on my controller when I hit the controller LVC the screen stays on but motor power is cut.
            When the BMS cuts off the screen goes black.
            is your BMS cutting power?
            It’s likely that the BMS has an LVC for each parallel group.
            The healthy groups compensate for the low one until it’s voltage drops to below the LVC, which happens at a much higher over pack voltage than the controller LVC.

            I have found a couple others with similar issues.

            Mine has 4500km (2800miles) most of the time charged to 80% and brought down to ~30%, roughly 180 charge cycles using a Grin Saitiator.

            This will be difficult to sort out. But unfortunately the pack is likely garbage. I don’t expect any manufacturer to warranty a pack this old, or any pack really. The fact it is potted makes the entire pack unrepairable.

            It could be as simple as one cell burning it’s fuse (Luna is proud of “cell level fusing”) and the others in it’s group being over/undercharged while making up for it until they are to worn to keep up with the “pack”

            I had expected to get at least 300 cycles being diligent about charge levels. At this rate the Luna Wolf cost me $0.13 per Km, my VW golf burns $0.15 per km.......

            it is unfortunate that one cell may have destroyed 41 others.


              I found another post with very similar issues....
              how many others are there that haven’t been posted?

              crap! I really thought this pack design was the best, what else is out there?


              I’m very tempted to cut the case off the potting and see if I can find a bms wire, blown cell fuse, or anything else obvious. It would sure be nice to salvage something off this pricey pack.


                You can see in the photos of the liquid wolf that the BMS is in the top. If I was going to go after one I think I would stick it in my vertical mill and start shaving it down till something started peeking out at which point I could hopefully more positively identify what I was working with.


                  Another Luna Wolf post