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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
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    Wheel gadgets farmer

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  1. 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.
  2. 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.
  3. 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
  4. 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.
  5. 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).
  6. 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.
  7. 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.
  8. @Tilmann So bad what happened to you. I've heard the Germans are strict with rules but I didn't know they could be strict even when there is NO rule. What you have been submitted to is probably a world premiere. It's arbitrary and it sucks.
  9. Dead Ninebot One E+ due to battery issue.

    What do you mean by the sentence in bold ? The problem comes more probably from the charger. Connect the charger to a hair dryer (dumb load) then measure the current. If must be 2A, if not, your charger has a problem.
  10. Charge Doctor for INMOTION

    @nomad It's all sold out. I'll have some again only in 1 week or 2. Please, send me a MP so I'll remember to let you know when it's available. I'll also tell you the price and how to pay.
  11. Charge Doctor for INMOTION

    Discharging may refresh a battery only if it's NiCd or NiMH, not lithium batteries (LiIon, LiPo, LiPoFe...). When a lithium battery is dead, it's dead, unfortunately. I have implemented the discharge cut-off mode not for battery-refresh in mind but rather for testing purposes (for example for safely discharging to 0% without killing the battery in order to determine the exact capacity in Wh).
  12. Charge Doctor for INMOTION

    Yes. No. To store a LiIon battery, charge it to 30% (even 50% if stored for more prolonged periods, eg >1 year , to avoid reaching down 0% by autodischarge). For a 20S battery (Inmotion's battery), 30% corresponds to 72V so set the Charge Doctor to autocut by voltage ans set the threshold to 72V. For a 16S battery (most other wheels), 30% corresponds to 57V.
  13. Charge Doctor for INMOTION

    Good point. Yes, in the lastest version (2.04), the max cut voltage has been ported to 85V. Charge Doctors after october 2016 are with version 2.04. Most users prefer the autocut by current though, so it doesn't change much for them.
  14. Charge Doctor for INMOTION

    I have added INMOTION to my list of wheels compatibles with the Charge Doctor. A summary of the specifics of Inmotion wheels, especially concerning fast-charging, is on my blog. Cut & paste of the blog's thread below: INMOTION unicycles have 20S batteries (nominal voltage 72V, charger voltage 84V) instead of the 16S classic topology on most other electric unicycles. Models V3 and V5 use the “square Lenovo” connector and model V8 uses the GX12-3 pin connector (same connector and same wiring as hoverboards). Charge Doctors for IMMOTION wheels are now available, in single-input or double-input versions. Warning, IMMOTION battery packs have less capacity than Gotways or King Song’s. So when using the CD-double-input, check that your setup does not charge at more than 1C (see article on “charge currents“). The CD’s usefullness is not only in allowing fast charging, it is mostly in the autocut function to automatically stop charging at 80% or 90% to preserve the the battery and considerably extend its mileage. INMOTION (72V nominal/ 84V charger) Connector Wh Ah Charge* at 1.5A (1 charger) Charge* at 3A (2 chargers in //) V3 Lenovo 144 2 0.7C 1.5C to be avoided!!! V5 Lenovo 288 4 0.4C 0.7C V5+ Lenovo 460 6.4 0.2C 0.4C V8 GX12-3 460 6.4 0.2C 0.4C *For a 2Ah battery, 1C charge corresponds to charging at 2A. On LiIon batteries, a <0.5C charge is considered a soft charge, a >1C charge is not recommended. Charge Doctor double input with Lenovo connectors, for INMOTION V3 & V5 Charge Doctor single input with GX12-3 connector, for INMOTION V8
  15. Charge Doctor double input for IPS

    Oh, great idea. Such ready converter don't exist of course. But I can sell you the required connectors (if you know how to solder) or I can make the converter for you, just ask me when you order the Charge Doctor.
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