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hobby16

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hobby16 last won the day on August 4 2015

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About hobby16

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    Bordeaux
  • Interests
    Wheel gadgets farmer

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  1. hobby16

    Charge Doctor Order.

    Yes indeed, I make the Charge Doctors on my spare times. So it's not always as smooth as I wish because of only 24h per day. Thank you Chriull for intervening.
  2. hobby16

    Charge Doctor Order.

    I haven't sent to Canada in the last 2 weeks so your order has not been served. I had vacations so there is lack of stock and some delays lately, all my excuses. But orders are always served, even if I don't send acknowledgement to payments (my selling system is by email, so very primitive, but it works). Of course, if I stop selling, the first thing I'll do would be to put my "buy page" down, to avoid unshipped payments.
  3. hobby16

    Ninebot Z10 - power supply Charge Doctor mod

    At low bat, I have the beeping when exceeding 15-20km/h. The beeping is not constant , only when I accelerate. Then the wheels tilts up and forces me to stop. A somewhat different behavior than what's on your wheel, probably because we don't have the same firmware (I've updated to the latest firmware using the app). What's annoying is the bargraph is not linear. It's something like 3 bars = 0-80% trip, 2 bars = 80% -95% trip, 1 bar = 95% to 96% trip, then the wheel stops.When I can't ride anymore and have to step down and push with the handle, there is still 1 bar on the bargraph while it should be zero or some flashing. So the display is misleading and unhelpful, I really hate how it has been programmed. Thank you for the toochain info. It makes total sense, especially with Freecad, which is a real 3D modeller, I've tried it and found it great. I'll dust off my 3D printer for a try.
  4. hobby16

    Ninebot Z10 - power supply Charge Doctor mod

    Nice setup, Christian! And nice 3D printout's color, the chargers and the Charge Doctor are in a cozy place. When unplugging the second charger, the charge current drops from 4A to 2A, so it's normal that voltage by drops delta voltage = R.I, R being the resistance of the charging chain (wires, connector, bms, protection diode, cutout mosfet...), I = 2A. I don't understand your question about "voltage bleed". As to charging to 100%, you don't need to disengage physically the Charge Doctor, you can do it by the CD's menu (2 or 3 clicks). I presume that's what you did, if not, check the user manual to see the steps. And yes, going from 95% to 25% is always better than 100% to 30%, because you avoid charging to 100% hence avoid the risk of overcharge. On monowheels, 0% (indicated by the app or when the wheel stops running) is in fact never 0% but rather 5% or even 10% because discharging to 0% is really bad and the firmware avoids that. You can recharge immediately or wait if the wheel needs to cool down, it doesn't matter much because even 4A charging is still a too small current to risk heating the battery. With the Charge Doctor and autocut, it's better to charge 5 small charges than 1 big charge. On the Z10, I find that the iddle current is quite high, maybe because of the BT module (just a wild guess). I've left the wheel one week and it doesn't power on because the battery is too low. I must recharge it to get it on again. Never have had such behavior on my other wheels (Inmotion, Goway...). It's something to follow up but if the problem is real on every Z10, this mean that for storage, the battery should be charged over 50% (instead of say, 20%, 30%) to avoid that the iddle current ends up draining the battery. I''ve just updated the Z10's firmware, so we'll see what happens to that iddle current. BTW, an off-topic question, what's your tools chain to 3D print ? I've bought a 3D printer with a dozen of filament rolls but never took time to make it work because I found the software setup seems so wild (maybe just a false idea). I am rather proficient with drawing with Sketchup but I don't know where to start to translate drawings into 3D printings.
  5. hobby16

    Ninebot Z10 - power supply Charge Doctor mod

    Yes it is an issue. Not serious but it is still a non-optimal use of the LiIon batteries. Compounded by the fact that many experienced people still see their wheel's battery (LiIon) like car battery (lead acid) and think keeping it charged at maximum is good. Old habits die hard. But we certainly can agree that the problem is case dependent, some batteries are too small compared to the needed range so the user needs to charge to 100%, some BMS are good and some are an abomination. Autocut of charging at 80% or even less is more for users with high end wheels and big batteries where range and high currents are no problem. As to the membrane stress, it's not something only due to overcharge, it's proportional to voltage, UniversityBattery has some good writings about that. So the less than 100% you keep the battery from, the better. That's why LiIon are stored at 30% to 50% and not 100%.
  6. hobby16

    Ninebot Z10 - power supply Charge Doctor mod

    No offense, but you are utterly wrong here. Look up any BMS datasheet or even better the IC datasheet, you'll see that overvoltage detection is always higher than the constant voltage threshold 4.2V. Most have 4.28V over-voltage thresholds, I have even measured some up to 4.35V thresholds, all legitimate BMS in brands like Xiaomi or Minimotors. Add to that the tolerance of about 0.05V on the component accuracy and the risk of overcharge becomes statistically significant. I assume I don't need to discuss your other generalities, some ok, some questionable, but all irrelevant to the fact that stopping the charging sooner than 100% is ALWAYS beneficial to the battery by not only reducing the stress on the cell's internal membrane (see e.g BatteryUniversity) but also by virtually eliminating the risk of overcharging. I prefer to ignore your ad-hom about " people just repeating stuff they don't really understand", it's unsubstantiated, unkind and unnecessary. Your argument should stand on its own merits and so far, I am not impressed.
  7. hobby16

    Ninebot Z10 - power supply Charge Doctor mod

    I agree that lower voltage increases current. But not that much as to impact significantly the battery's life. For example if you charge to 58.0V (80%) instead of 58.8V (100%), the difference in voltage is less than 2%, so is the current. A non significant difference. On the other hand, charging to 80% instead of 100% eliminates all risk of overcharge which has a huge negative impact on the battery's lifetime. Don't forget that all the unicycle's BMSs do balancing by current "bleeding" with a rather small current (50 to 100mA) compared to the charge current (2A or more). So as soon as a cell is slightly off-balance, it is always in an overvoltage situation as soon as the constant voltage phase is reached, precisely because the bleeding current is too small. That's where the cell's life, hence the whole pack's life is seriously reduced. When charging only to 80% or 90%, no such problem exists.
  8. hobby16

    Ninebot Z10 - power supply Charge Doctor mod

    Ninebot monowheels and gyropods have used so far 15S batteries ie, 54V nominal (value used in battery specs) and 63V max (value on the sticker on the charger's back). They have "downgraded" to 14S batteries (51V nominal, 59V max) on the Z10, which is a technical error and a regression IMHO. Powerful wheels need higher voltages to reduce ohmic loss, it's not as if the wheel diameter was too small to allow for more wiring (associated to higher voltage), there is plenty space in a monowheel's motor! The trend for higher voltages is general on other high end wheels like Inmotion V8, V10, GW, KS18L (20S, 84 Vmax) or even higher with the GW 100V (24S, 100 Vmax). The plus side of this blunder is 14S chargers are much more common, hence easy to find and cheap. They are used on a lot electric scooters, like the Speedway 4, you can find them around 30 euros. Of course, Ninebot must find a way or another to screw the wheeler, by using a from-the-outer-space connector in order to sell its proprietary charger. But a generic 14S charger with GX16-3 connector (like on the Speedway 4) can be used to charge the Z10 with the hack described by @Lukasz (awesome hack, kudos to Lukas). BTW, if someone knows the name of this bl@#&! Z10 connector (which is also now on some lastest Ninebot gyropods), I am interested. I've searched it sometimes now for the Charge Doctor, without sucess.
  9. hobby16

    KS14C Battery Charge/Discharge Curves

    It's probably the 14C control board's voltmeter function which has not been correctly scaled. The difference is rather big and weird. Several causes : - charging has been terminated a bit early. As you said, waiting until current drops to 0A would add some Wh to the total - difference in discharge and charge currents accounts somewhat for the difference in Wh because energy loss (in the wires and inside the cells) is not the same depending on the current. I have seen it when comparing charges at 2A then at 4A. - when charging at high currents, expect that the battery needs some "relaxation" time. If you let it rest some hour and plug the charger again, you can put in some more Wh. The tilt-back threshold is probably not much usefull here because your board does not measure correctly voltage anyway. You can detect the tilt-back by discharging down to 56V then ride your wheel back and forth on the same place until the tilt-back occurs. As to the low voltage detection, from what I know on my wheels (GW, Firewheel, Airwheel), it is based on the instantaneous voltage, with no real filtering: a big acceleration (when the battery is small or near empty, that causes a rapid votage drop) is enough to trigger instantaneously detection (tiltback on firewheel, beeps on GW). The stop voltage is very dependent on how you ride. If you keep the speed low and constant, the wheel will have hard time detecting any voltage drop as low threshold so you can ride very long time. If the ride is fast and/or with many acceleration, the tilt back will occur much sooner. Riders with many hours on their wheels can easily sense when they need to reduce speed for more safety because when the battery is emptying, the wheel becomes less powerfull and less responsive to accelerations. Anyway, your 14C has a quite big battery so it should be easy to find the max & min voltage to ride safely while keeping a decent range.
  10. hobby16

    Inmotion V8 or Gotway Msuper V3?

    Thank you, it's good to know. More points to the Inmotion as my next wheel. A soft/wavy wheel is outright dangerous when riding at more than 20km/h or jumping curbs or hitting holes. Even on a low-speed historic Solowheel (v.e.r.y wavy), I find it scary. It's the "comfortable mode" on my Firewheel and I avoid it as pest : hitting a hole when the wheel is "wavy" means that I already fly while the wheels tries to get me back to vertical. The "comfortable" mode has failed me many times and it's not so comfortable since it stresses me out so much. I ride at 25km/h so I now systematically use the Firewheel's "sport mode", hard, ultra-responsive and safe.
  11. hobby16

    Charge Doctor for INMOTION

    @Bram, I totally agree. With a 1.5A charger, current cutoff gives a limited range : setting the threshold at 1.3A will probably cut at 90% but not lower (some lucky V8 users with a 2.5A charger have more leverage). Whereas with voltage cutoff, you have more resolution in the threshold and can autocut at much lower level, eg 80% or even 70%. As to the fluctuation, as hinted by @FreeRide, it is due to the charger which has some "hesitation" when passing from the constant current mode to the constant voltage mode. Maybe it's by (bad) design, maybe it's specific to your particuliar charger, to be determined by more data from other users. Anyway, not something to worry about, imho. I have added a line to my table to highlight the benefits of partial charges on extending the battery's mileage (table's second line, calculation method described at the end of the table). I didn't remember it's so substantial but it is, theorically! http://hobby16.neowp.fr/2016/12/01/voltage-threshold-on-charge-doctor/ Cells 0% 30% 60% 70% 80% 90% 100% Total discharge cycles* 1800-3600 1200-2400 950-1900 700-1400 500-1000 300-600
  12. hobby16

    Charge Doctor for INMOTION

    The apps are not at all reliable, their soft are always sloppy. They take no data from the BMS (like eg the coulombmeter), only the voltage and deduce from it the % of charge, no wonder it's not a consistent value. As to the amps fluctuating, I have the same thing on one of my battery packs and it's a pack with a defect cell! Maybe your pack has the same problem, maybe not, hopefully (because 20S packs may have another behavior). As to the grapher KST, I don't know what's is wrong but I can say that Win10 is not the culprit. The problem may come from the config file, the path to the ascii datafile... KST may be hard to set up (some happen to get it work first time) and the interface is nightmarish but once it works, it works flawlessly.
  13. hobby16

    gotway mainboard in firewheel

    Horizontal and vertical correspond to the gyroscope's X and Y axis respectively. The board is programmed with a fixed setup for X and Y so the two axis are not permutable and what you need is not possible. You should probably have to remove a battery pack of the Firewheel to make room for the GW board. The problem is the FW battery system is such a mess (two packs sharing one BMS).
  14. hobby16

    Dead Ninebot One E+ due to battery issue.

    smallexis is ze reference as to Ninebot stuffs I made an error indeed, I wanted to say "to short the discharge mosfet" (transistor X1 in my link above). I know it has worked for at least one wheeler. The battery is not protected against overvoltage anymore but it works. The charger is voltage-limited anyway so the risk of overvoltage is zero if basic usage precautions are made.
  15. hobby16

    Dead Ninebot One E+ due to battery issue.

    @Dima Ninebot's people won't give you any relevant answer I'm afraid. They'll just tell you to buy stuffs. Your problem can have several causes, more info is needed to know which is the real cause : - Charger problem. It can powers up the wheel but still be faulty. Can you check it by the test above, yes, no ? - battery problem. Saying the "voltage is normal" means nothing unfortunately. The voltage of all the cells must be the same and in the range 3.3V to 4.2V per cell. What is the voltage of each cell and the total number? Without numbers, hard to tell. - BMS problem. There is a simple solution by shorting the BMS' charge mosfet (see schematics in my thread on BMS http://hobby16.neowp.fr/2015/07/21/bms-how-to-make-your-wheel-safer/ ) but the 2 causes above must be ruled out first.
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