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  1. GGoodrum

    Nuvinci developer kits for cheap

    I received the 20" rim and spokes I got from JR and yesterday I finally took everything to a local shop to get the wheel built up. I have the 36T Staton sprocket/freewheel adapter and most of the v4 drive bits now, so as soon as I get the wheel back I will start putting everything together. The...
  2. GGoodrum

    12s2p LiPo pack kit including 12-channel BMS "Lite" Board

    Not quite. What I'm saying is that if you charge both packs together, at the same time, it is going to take twice as long to charge, compared to charging just one of the packs. So, if you charge one pack first, and then charge the second pack, it is going to take about the same amount of time...
  3. GGoodrum

    12s2p LiPo pack kit including 12-channel BMS "Lite" Board

    Actually, with one MW supply, you can charge each 12s pack separately in the same amount of time that it would take to do the two in parallel, and you don't have to disconnect the discharge connections. This new design includes balancing, so you will have balanced charges every time. :) -- Gary
  4. GGoodrum

    12s2p LiPo pack kit including 12-channel BMS "Lite" Board

    Yes, two of these can be put in series, to make a 24s/88.8V pack. You can either charge the two packs with two 48V supplies/chargers, or with one big 96V version, if the charger + lead from the first pack is put in series with the charger - lead from the second pack. I really wouldn't recommend...
  5. GGoodrum

    12s2p LiPo pack kit including 12-channel BMS "Lite" Board

    Okay, we are getting closer. :) We made a slight change to the HVC control philosophy, which improves a number of things. Previously we had the HVC opto outputs in series, and then used this signal to trip the EOC shutdown logic. The idea being that once all the shunts were fully on, the cells...
  6. GGoodrum

    12s2p LiPo pack kit including 12-channel BMS "Lite" Board

    Yes, that is correct, there will be a version that doesn't require the CellLogs, and yes, the throttle LVC will still be used. I have yet to find a better way to kill the load on the cells. It is elegantly simple and extremely reliable. I will do the same thing with the CellLog version. All...
  7. GGoodrum

    40S (170v hot) ebike battery. Anyone ran higher yet?

    Luke, I think you are spawning a whole new class of Darwin candidates... :roll: :mrgreen:
  8. GGoodrum

    40S (170v hot) ebike battery. Anyone ran higher yet?

    You could blow the caps. You need to provide some headroom, so if you are going to run at 200V, the caps should be rated at about 250V. -- Gary
  9. GGoodrum

    12s2p LiPo pack kit including 12-channel BMS "Lite" Board

    The short answer is yes, both the LVC and HVC trip points can be set, if the CellLogs are used. Having a settable LVC point, is not all that important, in my opinion, due to the nature of how LiPo cells behave. With SLAs, for instance, a full battery starts out at around 14V, and is down to...
  10. GGoodrum

    12s2p LiPo pack kit including 12-channel BMS "Lite" Board

    A CellLog is a handy little widget that accurately monitors up to 8 cells in a battery pack and has various display readouts for showing the information on each cell. It also has various alarms that can be set, such as individual cell low voltage and high voltage trip points, overall pack limits...
  11. GGoodrum

    12s2p LiPo pack kit including 12-channel BMS "Lite" Board

    Getting closer, actually. :) I've got it down to two variants now, the shrink-wrapped, all-in-one standalone version, shown above, and a new variant, shown below, that will work with, or without two CellLog units. This will support three types of setups, a full CellLog-based 12s BMS, where the...
  12. GGoodrum

    Nuvinci developer kits for cheap

    Glad you got this working. I think you are the first one. :) Can you elaborate a bit on what you mean about not being able to control it manually? I'm very happy to hear that it can shift under load, though. I'm still not clear about how the whole shift table option would work. -- Gary
  13. GGoodrum

    "Zephyr" - Finally, the "v4" Fechter/Goodrum/Hecker BMS...

    That is the normal behavior except when you have the case where one, or more, cells are significantly out-of-balance. What happens in that case is that the shunts themselves can't hold the high cells at the 3.60V point, and they get "swamped". When that happens, the high cell voltages will try...
  14. GGoodrum

    12s2p LiPo pack kit including 12-channel BMS "Lite" Board

    Okay, I ran into a couple of layout issues with the "boxed" approach, which can be fixed in the "production" version. The good news is that the circuits work as advertised, which is not really a surprise because they have been tested many times now, but this at least verifies that I didn't screw...
  15. GGoodrum

    12s2p LiPo pack kit including 12-channel BMS "Lite" Board

    The boards for the version shown above will be here this afternoon. I will build up one complete set and do some tests. After I get this going, I'll go back to looking at the original layout, with everything on one board, if there is enough interest. Like I sad before, I need to do something to...
  16. GGoodrum

    Direct-drive 3220 setup with a 3-Speed Hub...

    My Nuvinci setup will be very similar, except that I'm now going to use one of Matt's drives as a first stage reduction. Its output has a freewheel, that drives the Nuvinci sprocket, except instead of a 27T, the one I got from Staton has 36T. In any case, pedaling will move the motor chain, but...
  17. GGoodrum

    Tppacks.com, Zippy Lipo 48v 15ah, LVC and Hyperion 1420i

    If you start out with balanced cells/packs, I think it is fine to parallel just the main 12s +/- connections, and not parallel the intermediate connections. This is how I've been building LiPo packs since the beginning. All the cells are still paralleled at the cell level. --Gary
  18. GGoodrum

    Tppacks.com, Zippy Lipo 48v 15ah, LVC and Hyperion 1420i

    It's looking good, so far. :) I have one of those crimping tools, but it is still a pain. I like that you soldered yours as well. Even with using the crimper, if it isn't just right, you can have one pop off. -- Gary
  19. GGoodrum

    New CellLog-based BMS "Lite"...

    Yes, I was, and they work, but I've got some packaging issues, getting it all to fit in the small box. I've had to back-burner this version until I get the 12-channel "kit" version finished, which is described here. After that gets going, I'll get back to this, and sort out the layout issues...
  20. GGoodrum

    12s2p LiPo pack kit including 12-channel BMS "Lite" Board

    This, I believe, will be the "final" version. In addition to the long LVC/parallel adapter board, for the horizontally oriented shrink wrapped packs, I've added a new dual LVC/6s4p parallel adapter that can be used with any pack configuration. The "boxed" portion, which has the balance...
  21. GGoodrum

    12s2p LiPo pack kit including 12-channel BMS "Lite" Board

    After thinking more about the layout, I decided to split the functions, and put the LVC circuits down on the board that gets embedded with the pack. That way, the "box" doesn't have to be connected during discharge. The box then becomes a simple "CMS"/auto-balancer that plugs into the pack for...
  22. GGoodrum

    12s2p LiPo pack kit including 12-channel BMS "Lite" Board

    Well, the heating issue is just postponing the single package version, but not cancelling it altogether. I've got some ideas to deal with the heat issue, and I'll get back to this variant soon. This new "boxed" version will support a wider variety of pack configurations, not just the...
  23. GGoodrum

    12s2p LiPo pack kit including 12-channel BMS "Lite" Board

    As I said, testing continues. A couple of issues, beyond the wiring errors, have arisen that I'm dealing with right now. The first is that the shunts are coming on a little low, like around 4.09-4.10V, instead of the predicted 4.14-4.15V. I'm tweaking the values a bit to raise this up. The other...
  24. GGoodrum

    Acid test - Mountain Climb- 3220 motor hv160

    Even one of these motors is crazy powerful, but two? I have a really hard time thinking these don't have enough power, whatever the gearing, to get a 100 lb trike up this mountain. If it were an HV160 controller problem, they would've fried, for sure, but they were lukewarm. I still think a...
  25. GGoodrum

    12s2p LiPo pack kit including 12-channel BMS "Lite" Board

    Soon. :) I had a couple of errors on the first test boards, and its caused a bit of a delay. Testing continues, however. -- Gary
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