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Chriull

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Chriull last won the day on November 8 2018

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About Chriull

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  1. Put your phone in a belt bag just at the belly - he is very sensitive to vibrations!
  2. Maximum speed is not increased by a higher battery capacity, but one can drive faster for a longer time. (Battery voltage dependend third alarm) And for any sudden burdens the voltage sag and "current availability" will be higher - so increased safety margin/"higher performance"
  3. Just made it through the topic, since i got things like the often high current alarms a bit late, to look for maybe other points missed... Here some points gathered For the 100V version, especially the 1230Wh - does anyone know how the battery configuration is? 24s4p with ~3500mAh cells or 24s6p with ~2300mAh cells? Especially with the high current demand reported hopefully it's a 24s6p configuration - 4p could already be borderline by too much voltage sag? Gotway seem to have some way/tradition of "hiding" their Mosfet/heatsink temperatures and by this seem to be the most "performant" at the hill test - until the mosfet fuse blows. V10F is the other extrem - imho the only one measuring the heatsink temperature and giving an overheat alarm before every other wheel. For paste and pads the thermal resistances vary with about a factor of 10 (over maybe even more - did just a quick check...), depending on the "quality" choosen. With the paste one has to use some insulation plate (mica plate/disc) and apply a continously _as thin as possible_ paste film on _both_ sides of the mica disc, or the thermal conductivity is not guaranteed. This is true for thermal paste and insulation, too. As written above - mica plates (as i was used too in "ancient" times) would be a possibility. But with the manufacturering quality control probs that's no possibility - imho thermal pads (of good quality) are sufficient and the best choice with at least some chance to be applied correctly. As it seems by now there exists pads with protective (?plastic?) foil - so they found a way to even spill this easy method... That's the next "problem" - the right compression is needed in any case. Too low of a force and there is no good contact, too much force and the mosfet "bends up" at the body part, were good contact would be most important! Most manufacturers recommend spring clips to prevent this problem and get a good, sufficient and evenly distributed pressure - especially at the most important points! Spring clips have the additional advantage, that no plastic insulation parts are needed to insulate the screws - as (some) plastic could "creep" over time and the pressure gets "lost". That's a pity - would be great to have logs of all tested wheels at overheat hill! As one sees on Rehabs foto below, at least the "outside" row of mosfets should be easy to inspect. One could even peek under the thermal foil if there is some plastic foil forgotten. Just the "inner" row hidden by PCB and heatsink will be tricky to inspect - but maybe using some flashlight and peeking inside (?with a mirror?) could reveal some "reflections" of forgotten plastic foils?
  4. For instance PET has about 20-50 times the thermal resustance than thermal paste - leading to 20-50 times the temperature drop per Watt... Did not get this point to this full extend before - higher currents more often with "smaller" mosfets... Poor mosfets! Additionally with prevented/hindered cooling... @Marty Backe - got the nikola so much more "aggressive/reactive? Just top speed motor power did not make such a big leap compared to the last models? Another explanation for much higher currents could be a higher lift cut off speed and/or a bit slower driving speed? The smaller Mofets can not be the readon for the current, they just fry earlier... ... or by some new firmware version the reported current is a bit more off than it was before?
  5. Btw, do we have any active GW representative still here? @Linnea Lin GotwayGotway seems to be not here anymore?
  6. Because the temp sensor is measuring the compartment temperature somewhere, but neither mosfet nor heatsink temperature. It has. Plastic is a really good thermal insulator. If one wants to destroy any power electronics that uses heatsinks decouple thermally the mosfets - thats one of the most effective ways...:( ... and they survived... As said, the compartment temperature rises much slower, and mosfets have unfortionately a positive temperature coifficient – the hotter the get, the higher their resistance gets and the higher the dissipated power, so the temperature rise gets out of control and they fry before any alarm gets triggered. Maybe a temperature sensor on the heatsink, as inmotion uses it could have helped, but on the other sude the mosfets were thermally insulated from the heatsink... Would be even worse, if beside a grave production failure there would exist a firmware/design fault, too... +1
  7. Was this repairs done by inmotion usa? Maybe @Liamfind from inmotion hq wants to chime in?
  8. Wow! Applying(forgetting) a thermal insulator between the mosfets and the heatsink is almost an intentional hazard! At least grossly negligant! I am very happy that you made the overheat hill test to find this out! Don't want to think about a possible outcome of you driving with 30+ mph and the mosfets fry.... *shiver* Edit: ps: really a pitty! GW improved really well lately quality wise and now such a grave mishap... Hopefully this was just one overworked, drunk or whatever whom happened this one time - or GW will ve known again for their mosfet fuses...:(
  9. And/or email and whatever other contact possibilities they have.
  10. @leffern My google lens recognizes this as 报警振动提示开关 Fed into google translate leads to "Alarm vibrating alert switch"
  11. I am very happy with it! Just the high pitched whine is nerving...
  12. One of the new ones - the ks16x or nikola, as soon as there are enough reports available. My last choice was the ks16s.
  13. Wär eine tolle Idee! Ich bin derzeit noch immobil, sollte sich aber hoffentlich bald wieder ändern!
  14. Ks16S is lighter, the Tesla stronger and faster....
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