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Everything posted by Chriull

  1. If one respects the limits of this wheel one will (most likely) not faceplant Also with the much stronger gw tesla faceplanting is possible, like seen short time ago (also the real reason is not known by now - chances are existing that it was just pushing the wheel beyond it's limits) ... So in the end the driver is still one important reason for faceplants ... For most wheels replacement covers are available, so they look shiny and new again. Also some people use neoprene suits to protect their wheels...
  2. It has 25% 1 star ratings - defective wheels, batteries not chargable again, ... someone got a punch of defective wheels - s1‘s that did not pass the tests? Returned wheels?
  3. @e.motion the 1200w nominal power of the S vs the 800 W nominal power is a totaly new experience! Comparable to my step from the 500 w ninebot one e+ to the ks16c with 800W. Once with my ks16c i did not see a "negative bump" while crossing a road, got an bad forward lean by this and was sure i will crash into the asphalt - with some short delay and an adrenalin rush the 16c accelerated below me and everything went well. I'm quite sure that with the e+ i would have crashed and with the ks16S i would not have any story to tell (nothing felt/happened)! Btw: the S is one of the new generation wheels with thicker(stronger) axles!
  4. @Smoother imho the orientation of the sensors matters - the output/voltage/resistance is proportional to the magnetic field and by this has to have a direction? But imho you meant the "relative" position along the wheels circumference by mentioning the 3 o clock versus 6 o clock position? As long as you shift all sensors by the same angle i could not imagine any prob (which does not have to mean anything 😎). Best to ask our members from the firmware thread - they should have the most knowledge regarding this topic! But i cannot really follow your thought - why not leave the hall sensors where they are? I do not see any need shifting them only because you change the axle "rotational angle"? But again - involve our firmware guys to gain some real practical knowledge?! Ps,: the relative position of the hall sensors in regard to the coils along the circumference could matter?!
  5. I would go the 250€+ for the ks16s - a total dufferent wheel as the C and more than worth the price difference! I'm not very sure if they did not offer recently the ks16s quite cheaper (indroruction offer?) - the shop owner/a representative is also a member her. Maybe you get a forum rebate 😎. Also a great decision! Have fun riding!
  6. @Philip Yepes you already tried deinstalling and reinstalling the app?
  7. Yes - there are for sure many for example ninebot one c/e+ users which are after sone years still satisfied with the wheel! Its just suggestions we can give, the decission has to be made personalky to meet ones requirements/desires. Not beeing the newest and most powerfull wheel the S2 still can be the perfect choice...
  8. Battery replacement

    For example this is also quite amigous - did you buy a replacement battery for a hoverboard or did you buy the replacement battery for exactly your hoverboard? From the photos they look as they could be a bit different? .. or not?
  9. Battery replacement

    I am quite sure that you are not hiding anything by purpose - but you are still nit giving us enough information to present you sane proposals. As you yourself do not recognice this, its even more important to know every detail - dealing with li ion batteries can be very dangerous! Here are mostly electric unicycle riders and not too much till none hoverboard specialists. Hiverboards have many similarities to eucs, but still many different details! So we cannot provide some magic solution by looking at some photos of some details...
  10. Welcome to the forum @e.motion! The S2 is the "oldest" wheel, has imho just something about 500W (did not find the motor power while googling)? But it could have be the smallest and lightest euc of your selection? ( Also not really sure about this). One can also break ones teeth and chin with 20 km/h 😥. (1) For safety motor power is important (the 3kw advertised for the ks14d is just wrong). A nice overview of the capabilites can be found at https://airwheel.ru/2017/10/27/test-monokoles-na-dinostende/. The less capable a wheel is, the easier one can overlean it and risk a faceplant! But what i remember from the forum reports, there were not much probs reported from the S2 - just quite recently some battery probs... Reaching just about half the advertised range is quite "normal" for all wheels - with some hills it can get even less. The advertised ranges can eventually be reached by weighing 50 kg and driving slow on a flat road... For off road driving a 16 inch wheel should be the better choice! You did not mention range you'd like to go between recharging - quite an important point! If one likes EUC riding, normally one tends to go longer and faster - so the first wheel will be to weak within a couple of weeks/months... Especially bicycle riders which overtake one all of the time are very annoying 😎. To "prevent" this 30-35km/h max speed is very nice. For kingsongs top speed can be reduced (tilt back and alarm speeds can be adjusted freely), imho also the "hello kingsong" message can be turned off for all kingsongs by now... Imho one of the nicest allround wheels by now is the ks16s ... But costs again more than your choices so far... There were also some other "beginners choice" topics here recently to gather some information, and of course many wheel specific reports/discussions... Edit (1): the only real protection here is a safe helmet with chin guard (or maybe get some intense parcour training a couple of years before 😎)
  11. Ninebot One S2 - Only one side charging?

    Maybe battery 2 is disconnected (bms shut off for whatever reason) showing no current flowing? Maybe also a connector problem? Battery 1 has 6387 mAh of a total capacity of 2850 mAh left?
  12. My Mten3 Broke and What I'm Doing About it

    Grats! But even if the voltage is the same by now, this one or two cells still could have the chance to be worn down a bit by this incident and that just their second paralleled cell keeps up the voltage (by some extra stress). Or they just lost a bit of capacity and increased a bit their resistance... Or nothing happened and just the plastic cover was inflicted. Some discharge/charge cycles while watching the cells (temperature, looking for some "bloating") would have been a nice double check besides the optical inspection. But if everything is well put together again also comparing the charge curves with something like the charge doctor could give a hint (lost capacity). Even if you don't have past logs comparing future logs for possibly showing higher degradation could give a hint. (Also changes could be too small to be really distinguishable and by this hopefully lead to no real probs but maybe a bit shorter lifetime) ... Or you have just fun driving and are a bit more carefull while charging (smell, no unattended charging,...). If someting should be really wrong you'll notice it by shorter range and/or performance...
  13. My Mten3 Broke and What I'm Doing About it

    Looks like this nickel strip has to take quite some mechanical stress? Is it the only/one of the mechanical fixtures between the two packs? It melted nicely along the edge... From one website i found that a 10mm times 0.13mm nickel strip used to connect cells can carry 15 A. If it has this dimensions thats way too low to connect two banks of two paralleled cells. It would have to withstand the current of two paralleled cells ( ~2*10A nominal) - in combination with mechanical stress it mutates to a heavily underdimensioned fuse. As the nickel strip is also colored at the place it is welded to one of the cells i would not trust this cell anymore - could have easily got quite high temperatures! Edit : seem to be just 2 paralleled cells in total for the mten? So the nickel strip could be ok for nominal burden without mechanical stress, but still not for peak load with some deformation... Edit: would make sense that this nickel strip connects the the two 10s2p packs to a 20s2p pack?
  14. Welcome to the forum! King ma seems to not be on the forum anymore... But here are some riders with innotion v8 experience. As @Hunka Hunka Burning Love wrote it should go fine, inmotion is known for quite well build wheels. Also quite no EUC is really waterproof. There where imho quite some success reports of all kinds of wheels driven in (espessially ligjt) rain... Some reports were imho with smaller malfunctions (power button?) once in a while. To be on the safe side you could tinker yourself some rain suit for the V8!? Try to get the wheel well temperated to the parade! Batteries loose quite some capacitance and current delivering abilities at cold temps! Also you're going to drive well above sub zero temps, be prepared of possible "wobbly" behaviour, unexpected tiltbacks. Maybe make a testride at such temps before?

    Then the rider would just fall forward (overlean), but in the slo mo is seen that the rider also gets pushed upwards („ejected“) by the wheel turning forward violently. This can only happen by a blocked or max braking wheel. edit: imho it also does not look like the driver was lifted up by the bump and the wheel fell forward, but maybe this could be also a possibility not clearly to be seen? edit 2: maybe not pushed up by the bump, but by the tyre after it „bounced“ back after beeing compressed to the ground again? edit3 : watched it again - does not look really like edit or edit2..

    In the slow mo one sees the wheel turning forward in one instant - so its either a blocked wheel or max braking (without rider influence). Seems like some hardware/firmware failure induced by the bump/pothole short before - or its just some unrelated coiincidence? maybe a pebble stuck between shell and the casing, molten wires that shortened by the vibrations of the bump, a broken gyro, burned mosfets, or whatever else could have happened... but does not look at all like any normal overlean or cut-off. ps.: the direct link to the slow mo:

    Imho this was no cut off or overlean - then the rider would have „turned normally forward“ till the faceplant. In the slow mo the pedals are violently turning forward first lifting the driver up and then getting „hooked“ at his shins... so looks like quite a blocked wheel...

    In http://forum.electricunicycle.org/topic/8795-gotway-tesla-vs-ks16s/?do=findComment&comment=130547 the same video is posted with the accident in time lapse slow motion. Seems like the tesla just turned forward 90° instantly at the "bump" instead of driving over it... (Pure Speculation: Mosfets burned/something shorted the motor, so instant braking?)
  19. I had in my graphs a discrepancy between my power calculations for accelerations versus the real log data from wheellog. (http://forum.electricunicycle.org/topic/7855-anatomy-of-an-overlean/?do=findComment&comment=107766) Data from wheellog: timestamp, speed and current. Acceleration is Delta v / Delta t. As current power for this acceleration i used F = m * a, Pa = F * v. On the other side i have the motor output power which is Pmotor = I * U Back EMF. Both power should the same (ignoring friction&magnetic losses, air drag, etc and the "sampling inaccuracy" ) but here is an average error factor of ~2! I am tempted to just use Pa = m * a * v / 2 as formula , but imho that would be the average power to reach the speed v with an acceleration a. Pa = m * a * v should imho be the power needed to keep up an acceleration a at a speed v? Anyone has an explanation for this? If this power for acceleration formula is corect, then imho the only other possibility should be, that the reported currents from the KS16C are off by the factor of ~2 and i'd have to look if this can fit again somehow with the other measured data... m 100 kg timestamp speed voltage current speed Accel m/s² Pa Pmotor Error Factor U Back EMF s km/h V A m/s dv / dt Pa=F*v=m*a*v I * U Back EMF Pa/Pmotor 0,056 8,58 60,4 11,24 2,3833333 12,0978 0,244 9,42 59,84 15,16 2,6166667 1,241134752 324,7635934 201,358152 1,61287 13,2822 0,474 10,98 58,55 23,34 3,05 1,884057971 574,6376812 361,345212 1,59027 15,4818 0,667 13,29 56,7 31,93 3,6916667 3,324697755 1227,367588 598,333077 2,05131 18,7389 0,85 15,92 55,62 33,53 4,4222222 3,992106861 1765,398367 752,654616 2,34556 22,4472 1,038 18,61 56,65 30,53 5,1694444 3,974586288 2054,640301 801,110253 2,56474 26,2401 1,278 20,18 57,49 25,19 5,6055556 1,81712963 1018,602109 716,751222 1,42114 28,4538 1,459 21,5 55,38 28,38 5,9722222 2,025782689 1209,842439 860,3397 1,40624 30,315 1,64 24,09 53,04 33,81 6,6916667 3,974831185 2659,824535 1148,420889 2,31607 33,9669 1,899 26,47 52,28 34,93 7,3527778 2,552552553 1876,835168 1303,681911 1,43964 37,3227 2,044 28,72 53,52 30,7 7,9777778 4,310344828 3438,697318 1243,20264 2,766 40,4952 2,243 30,25 54,17 26,86 8,4027778 2,135678392 1794,563093 1145,64615 1,56642 42,6525 2,449 31,69 55,06 23,41 8,8027778 1,941747573 1709,277238 1046,026689 1,63407 44,6829 2,644 32,66 55,73 20,67 9,0722222 1,381766382 1253,569167 951,865902 1,31696 46,0506 2,913 33,66 56,23 18,22 9,35 1,032631144 965,5101198 864,732132 1,11654 47,4606 3,056 34,96 56,94 15,78 9,7111111 2,525252525 2452,300786 777,853008 3,15265 49,2936 3,251 36,14 57,97 13,02 10,038889 1,680911681 1687,44856 663,465348 2,54339 50,9574 Average 1,92774
  20. In because of this i just looked at the system "after the motor coil resistance", so this high losses are not in effect for this consideration. Could easily be, that with this sampling intervall some "main values" are "missing". Also one does not know if the values are all from the same point in time or from some point within the timespan, or averaged, or whatever... ;( This "example" above was choosen, because it was a phase of a somewhat "constant" acceleration phase. And my question arose if the available current data from the wheel is just off by some factor or my formulas are wrong... This 16 data points are however a very low number and chances are high that by some "asynchronity" of the sampling the deviation gets quite high/renders the data quite unmeaningfull... With constant speed and "no acceleration" i cannot "calibrate" the current(torque) leading to an acceleration. With constant speed just the torque to overcome friction, air drag and the provide balancing is existing. And all this values are new "unknowns"... Maybe some 5 to 10 minutes accelerating up and down in the underground garage gives some nicer data...
  21. The "power system" of on EUC works as follows: The battery supplies some "ideal" power = "ideal" battery voltage times battery current Then there is somy power dissipated internally in the battery = internal battery resistance times battery current ^ 2 Then some wire/contact power disspation mainboard/mosfet power disspation After the mosfets the battery voltage is "stepped down" by the PWM duty cycle, the motor inductance and the freewheel diodes (mosfet body diodes) or active freewheeling. By stepping down the battery voltage to the motor voltage the motor current has to be this same factor higher than the battery current. (**)This stepped down battery voltage is the motor input voltage Again some wire/contact power dissipation Then there is the power dissipated by the coil resistance: coil resistance times motor current ^ 2 After the voltage dropped at the motor coil resistance the back emf voltage is "left" (motor induced voltage). (*) This back emf voltage times motor current is almost the motor output power, there just some magnetic losses and internal friction. This now mechanical output power left now "satisfies" the external friction (tire on road) and air drag. The rest of the power is for acceleration(and/or inclines). I just looked at the system after the (*) - and there the losses/efficiency are for the concerned speed way below this error factor of 2 i had in my calculations. If one would look at the whole system, the main losses are as you stated at low speeds and high loads are the losses at the motor coil resistance (more or less the motor efficiency). (**) This motor input voltage is "regulated" by the firmware (PID feedback loop which sets the PWM duty cycle) to get the right motor current (torque) to keep the driver upright ("self" balancing)
  22. As written for the first step i did not care for finetuning and by this ignored the losses, friction, etc - i wanted to understand the error factor of ~2 if you are interested in this topic there is a quite perfect script for e-bikes, but covers all the basics needed for EUC's in german: https://ces.karlsruhe.de/~BUB/Umwelttechnik/Elektromobilitaet_TGJ14_2012.pdf (3 phase BLDC's can be simplified to normal DC motors as written in this script and by this easily understood) Or my steps towards this direction: http://forum.electricunicycle.org/topic/7549-current-demand-versus-battery-voltage/. But i'd recommend the former link - is much better explained and understandable That's why i made an average over all the values and compared this. This should sort out sampling problems, also it's just for 16 values. By now i'm thinking of logging with wheellog driving some slow and fast cirlces (in/declines get sorted out) and average the power consumptions and accelerations to get a correction coefficient for the current... (without really knowing why). - on reason could be the current flowing through two coils with 120° difference. If one makes a vector addition of the two "forces" created by this the sum is by the squareroot of 3 bigger (1,7...). Maybe i have overdone with the 100kg weight and additionally some sampling variations did the rest and this is the factor? That kingsong reports just one phase current and the effective motor current goes by this factor? - the measurement of the motor current is just inaccurate and has to be corrected for each wheel/batch? Sorry - that's the excel time/date formatting. It only shows a max of 1 digit after the comma (decimal point ). I've made a recaluclation and formatting of this in the sheet and going to edit the above posting to the full 3 digits after the point/comma. Thanks for looking at this in this kind of detail level! Because it's called comma here - don't know why you call it decimal point... Thats motor current times the Back EMF Voltage (or also called motor induced voltage). Minus some magnetic losses and internal friction. Resitances are, as written ignored by now - that's finetuning once i understand or give up understanding They would just count for some (major) percentages but not for an factor of 2. The mechanical output power of the motor which is as written above motor current (direct proportional to the torque) times Back EMF Voltage (direct proportional to the speed) is by this formula/definition direct proportional (dependend) on torque (load) and speed. The electrical power supplied by the battery and/or the electrical motor input power in relation to the motor output power depends on this motor efficiency and cannot be ignored (would lead to error factors much higher than two). But here this is not looked at. By just taking the motor output power (i_motor times back_emf_voltage) just some small magnetic losses and internal friction are "ignored" (some percents of efficiency)
  23. Choosing first EUC

    @VicW Welcome to the forum! There are now also some other "choising first euc" topics going on, where you can get some ideas. Here are also many reviews/reports/discussions about quite all the unicycles. Important points missing in your post is the range you expect to drive between charging. Also if this "range" us only on flat terrains or containing many steep inclines! Imho also walking with an EUC regularly for longer distances could be quite cumbersome (especially depending on the terrain...)
  24. Help a Newbie Decide and Get Going!

    This with your requirement could get a bit tight. With ~90 kg i'll get something between 30 to 40 km in hilly terrain (much inclines) with my ks16s. If you'r trip is in flat terrain 30 miles are no prob for the ks16s - and still some surplus. You should in any case also look for the big wheels like msuper v3s+ and monster from gotway. They'll give you the range with ease and could be more comfortable for long commutes? @Marty Backe? I'm not sure if i understand the meaning as non native english speaker, but i'd say EUCs are no really perfectly matured thing either... Not compared to cars, but maybe compared to e-skateboards? Just Fyi, if you've not seen this topic till now: My advice: then get at least two EUCs! With this also in a posting above mentioned inmotion/ninebots are out of spec. Ninebot could release a new wheel (Z) maybe not too far in the future. "Real" Cut offs could be about the same. Some vendor stats where published here and there are some more returns/broken mainboards with gotways, but imho not as much to be a "deal-breaker". There where also some reports about ks16s with bad motherboards here lately... @Jason McNeil (ewheels) has a great reputation and perfect feedback here. Seems like a strong reseller like him also guarantees you great gotway customers service! Tinkering: if one has bad luck maybe a mainboard has to be replaced, with very much bad luck a motor. But once they drive (from beginning without the bad luck) no tinkering is normaly needed...
  25. DarknessBot - iOS App

    Sorry @Ilya Shkolnik for linking a different app in your app topic, but somehow it happened and maybe gives you a hint to improve your app...