My 84-volt Nikola Triumphs, Tribulations, and Failures

[Marty Backe]

3 hours ago, TuN3M@N said:

Ohh come... until you post sources for reliable figures regarding overall sales figures for ALL markets and in addition to that detailed claim statistics goingt downt to part level  this is not more then an other online forum bullshit fairytale.

Why is everyone sticking to such kind of statements? Simply stay by the facts and we get a serious discussion.

 

Another Point is the possible failure potential. For sure burned voltage regulators, level problems(never had, didn´t know anyone had), battery drain, different charge levels and so on should not be neglected, BUT even the burned boards did not eject the drivers during ride. I myself do not know of any case in which his happened. 

It frightens me that Nils said "The Nikola is a much better ride in my opinion" over the V10F and Marty likes it. Serious… this thing is not able to read current as well as temperature in the correct way. There is no cooling concept at all... And NO a closed compartment air cooling is not a concept. At this point it doesn´t matter how it rides. With this configuration it is life-threatening not more not less.

But wait, in your first two paragraphs you say stick to the facts, but then in your last paragraph you start throwing out statements not supported in facts. This is so funny 

"this thing is not able to read current"  -- Really? Mine provides very nice relative current measurements like all my other Gotway wheels.

"there is no cooling concept at all"  -- Really?  Are you aware that this isn't the only Gotway wheel with a closed compartment, and the other wheels aren't burning up. The Nikola is a very cool running wheel.

"it is life-threatening"  -- Really?   !8*@%! fairy tale.

Those are all your opinions. Please stay by the facts, as you say.

[meepmeepmayer]

Thinking about this the last day or two, I'm (wishfully) thinking this really was just a manufacturing error. After all, even my shitty ACM mosfets didn't fry when my cables melted. So it's unlikely the mosfets would have died with proper cooling contact.

Really grateful you plan to repeat the test with the new board, Marty! That will tell.

Still hoping for the Nikola100V/MSX(?) board on future 84V versions though (or at least on the 2100Wh which I'm aiming for).

[Harold Farrenkopf]

1 hour ago, meepmeepmayer said:

Thinking about this the last day or two, I'm (wishfully) thinking this really was just a manufacturing error. After all, even my shitty ACM mosfets didn't fry when my cables melted. So it's unlikely the mosfets would have died with proper cooling contact.

Really grateful you plan to repeat the test with the new board, Marty! That will tell.

Still hoping for the Nikola100V/MSX(?) board on future 84V versions though (or at least on the 2100Wh which I'm aiming for).

I can say with 99.99999999% certainty that the failure of those 3 mosfets was from the film that wasn’t removed properly during assembly of the board onto the heatsink. 

[Marty Backe]

14 minutes ago, Harold Farrenkopf said:

I can say with 99.99999999% certainty that the failure of those 3 mosfets was from the film that wasn’t removed properly during assembly of the board onto the heatsink. 

You just couldn't go the final 0.000000001% huh?

[Harold Farrenkopf]

13 minutes ago, Marty Backe said:

You just couldn't go the final 0.000000001% huh?

Nope. Because one of the mosfets might have failed after the others for other reasons.

[Kens]

16 minutes ago, Marty Backe said:

You just couldn't go the final 0.000000001% huh?

Cuz they might be  a 0.00000000051% the MOSFET is not beefy enough.

0.00000000023% because of cheap thermal pads.

0.000000000168% poor engineering.

0.000000000005894125% divine intervention etc..

[Unventor]

22 minutes ago, Kens said:

Cuz they might be  a 0.00000000051% the MOSFET is not beefy enough.

0.00000000023% because of cheap thermal pads.

0.000000000168% poor engineering.

0.000000000005894125% divine intervention etc..

Envy bicyclist sabotage? 

[Kens]

1 minute ago, Unventor said:

Envy bicyclist sabotage? 

That would be 0.00000000000089% only 

They are mostly harmless creatures. Only feeling superior in their $1000 bikes and hundreds dollar worth of skin tight suit.

[Lukas83]

5 hours ago, Unventor said:

Envy bicyclist sabotage? 

No! it was Chuck Norris! 

And to the Ninebot over the top lover: go and check the forum... there are a couple of threads where Ninebot e2 / s died during riding with severe injury... And we have a lot of Z10 with dead batteries on delivery. Like US69 said, the inner quality isn't that good. The shell - no doubt about it, looking great as well, and it rides pretty good, but the voltage, top speed and partially defective or wrong working bms is on another side. 

In time today I would never go for a Z10 - I would have a lot better feeling with msx, 18xl or Nikola 

[stephen]

8 hours ago, Lukas83 said:

In time today I would never go for a Z10 - I would have a lot better feeling with msx, 18xl or Nikola

You might get a (better) feeling with the msx,18xl or Nikola but you won't ever ever get the feeling of a Z10 till you have one which makes this wheel unique to any other wheel ,it's amazing how it handles slow or fast.

[Nils]

16 hours ago, Harold Farrenkopf said:

I can say with 99.99999999% certainty that the failure of those 3 mosfets was from the film that wasn’t removed properly during assembly of the board onto the heatsink. 

Yeah, I'm no electrical engineer myself, but I have to say that when I saw Marty's post I was both disappointed and angry, but I also couldn't really believe it. As I own both the V10F and the Nikola, and have done my own load test of both wheels I really didn't expect any problems with Marty's over-heat hill at all considering how the V10F fared for him (many clips there but as I recall overloaded in one of the tests but actually climbed decently for you Marty in others?). Just doesn't make sense to me.

Now as others have said I don't see why they would skimp on the MOSFETs in the first place to save a few bucks (just let us all have a large margin for error considering the nature of what we're riding here you cheap skates!) but just given my experience with my own Nikola and V10F this doesn't seem right. Of course, there could be other differences of course such as temperature (and the engineering decisions of the fans placement vs the temperature read-out that have been discussed).

A failure in workmanship/QA is not good at any rate and deserves its due criticism , but it's of course very interesting to get the truth of the matter - general issue with the design or one-off assembly error to human screw-up?  I'm leaning towards the latter and would love to see Marty do a follow-up with a new board, but I of course understand if you're not that keen on it @Marty Backe (but then how would you even know the truth for yourself, eh? . I'll donate towards the cause if needed).

[Dzlchef]

2 hours ago, Nils said:

Yeah, I'm no electrical engineer myself, but I have to say that when I saw Marty's post I was both disappointed and angry, but I also couldn't really believe it. As I own both the V10F and the Nikola, and have done my own load test of both wheels I really didn't expect any problems with Marty's over-heat hill at all considering how the V10F fared for him (many clips there but as I recall overloaded in one of the tests but actually climbed decently for you Marty in others?). Just doesn't make sense to me.

Now as others have said I don't see why they would skimp on the MOSFETs in the first place to save a few bucks (just let us all have a large margin for error considering the nature of what we're riding here you cheap skates!) but just given my experience with my own Nikola and V10F this doesn't seem right. Of course, there could be other differences of course such as temperature (and the engineering decisions of the fans placement vs the temperature read-out that have been discussed).

A failure in workmanship/QA is not good at any rate and deserves its due criticism , but it's of course very interesting to get the truth of the matter - general issue with the design or one-off assembly error to human screw-up?  I'm leaning towards the latter and would love to see Marty do a follow-up with a new board, but I of course understand if you're not that keen on it @Marty Backe (but then how would you even know the truth for yourself, eh? . I'll donate towards the cause if needed).

I think all of us that own Nikolas want to see Marty retest successfully.  I’m pretty sure it’s workmanship but I pucker up every time I’m aggressive and the wheel starts beeping at me.  Typically I have several 110A spikes every ride but yesterday I had one approaching 130A.  I’m trusting but a bit nervous! 

[TuN3M@N]

22 hours ago, Marty Backe said:

"this thing is not able to read current"  -- Really? Mine provides very nice relative current measurements like all my other Gotway wheels.

Ok, now  i understand that you are really thinking that this thing was throwing nearly continuous 90Ah current. Sorry but it wasn´t. Are you really thinking this thing tooks nearly 7kw to move you up this hill? I do not take it upon myself to estimate your weight, but this is also quite easy to calculate if you know the facts . Ist only a question of torque, rotation speed and efficiency of the BLDC motor. But i will take a rough estimate the motor will not work with 1-2% efficiency

"there is no cooling concept at all"  -- Really?  Are you aware that this isn't the only Gotway wheel with a closed compartment, and the other wheels aren't burning up. The Nikola is a very cool running wheel.

Because they have done this design fault several times it isn´t a fault? I still won´t believe it but are we really negotiating this point? This "concept" ist not a cooling concept, this is not more than a heat distribution system in a very small compartment. What do you think, how much energy is needed to heat up 3-5 liters of air from 30°C to 100°C? Let me go away from facts a little bit and estimate 5 liters of internal volume so you need roughly 7w(yes 7!) for 1minute(YES 1!)to heat it up to 100°C at 100% heat absorbtion. Isn´t it a cool cooling system . Maybe you will get a small cooling effect in the areas where the air is in contact with the shell but to be honest, ABS, PLA, PE and so on are quite more a heat insulation than distribution. That these systems stay alive is only based on the heat capacity of the circiut board carrier. Even if these ESC boards/board sections will work with 98% efficiency AND you "only" use 1000W you will get 20W for heating the air inside the compartment. What do you think how good will all the electronics workt at 100°C and higher? Will they burn?  

"it is life-threatening"  -- Really?   !8*@%! fairy tale.

It is a fairytale if this thing ejects you at 50km/h? Maybe but THIS will cause serious damage, quite contrary to a sleeping battery.

But in addition have you found the fact sheets from US69 regarding the ESC board failures rates form the Z10? Still missing them...

 

Edited June 19, 2019 by TuN3M@N

[US69]

20 hours ago, Harold Farrenkopf said:

I can say with 99.99999999% certainty that the failure of those 3 mosfets was from the film that wasn’t removed properly during assembly of the board onto the heatsink. 

That's all very optimistic...

Seeing that they used the small Mosfets again, the fact that the Wheel was the whole time steadily going over 90Amp, which until now no other Wheel did, and that even on the "Baby" hill?!

Seeing that and that the Wheel was not even running hot a Little bit….that the temperature not got up even over 50.

All this evidence makes me guess that it wasn't the Mosfet running to hot because of this Little film Peace..….my guess is that a to high amperage spike/draw killed the Mosfet.

At least that would better fit to other GW cutouts, too. These also were not because of running to hot, they were just killing the Mosfets by to high amps/hills/draws.

But Ok...not everyone Needs the same opinion…..

[US69]

10 minutes ago, TuN3M@N said:

But in addition have you found the fact sheets from US69 regarding the ESC board failures rates form the Z10? Still missing them... 

 

Dude...don't you get it that you are not been taking serious? Use the search Funktion on top of the board...it is something thats not that bad for new board members!

Some of your assumptions/opinions are that wrong...it is not even worth arguing.

[TuN3M@N]

15 minutes ago, US69 said:

Use the search Funktion on top of the board...it is something thats not that bad for new board members!

 

Using the search was of course my first attemp, but based on this i realized that there is abolutely Nothing reliable... 

 

Thats exact the point there are no facts all around these fairytale… 

15 minutes ago, US69 said:

Dude...don't you get it that you are not been taking serious? 

By the way becoming personal is for sure the most poorly way of communication.

Edited June 19, 2019 by TuN3M@N

[Harold Farrenkopf]

25 minutes ago, US69 said:

That's all very optimistic...

Seeing that they used the small Mosfets again, the fact that the Wheel was the whole time steadily going over 90Amp, which until now no other Wheel did, and that even on the "Baby" hill?!

Seeing that and that the Wheel was not even running hot a Little bit….that the temperature not got up even over 50.

All this evidence makes me guess that it wasn't the Mosfet running to hot because of this Little film Peace..….my guess is that a to high amperage spike/draw killed the Mosfet.

At least that would better fit to other GW cutouts, too. These also were not because of running to hot, they were just killing the Mosfets by to high amps/hills/draws.

But Ok...not everyone Needs the same opinion…..

Well, would you accept my evaluation if I told you that I am professional engineer in electrical engineering?  That film reduced the heat removal from those 3 mosfets that they overheated on a sustained high current switching and destroyed themselves inside which let the smoke out. The shorts inside melted the pins off some of them. 

 

As as the joke goes, the smoke makes it work and it’s escape is why it don’t work anymore. Lol

[Harold Farrenkopf]

Magic smoke. 

https://en.m.wikipedia.org/wiki/Magic_smoke

 

[US69]

2 minutes ago, Harold Farrenkopf said:

Well, would you accept my evaluation if I told you that I am professional engineer in electrical engineering?  That film reduced the heat removal from those 3 mosfets that they overheated on a sustained high current switching and destroyed themselves inside which let the smoke out. The shorts inside melted the pins off some of them. 

 

Sure the film did all that, Yip, it reduced A BIT of the heat  removal and sure i accept your Job Evaluation. Perhaps then you should also accept the 4years experience here with the GW boards with that small Mosfets.

Given the fact that other 84V 6p20s wheels(=same design) from Gotway all have the bigger Mosfets (on the same board), but the Nicola, instead using less amperage, seams to Need much more than those other wheels, for me this small Mosfet design choice is still a bad one, especially as GW has no "overamperage" protection...you overstress it, then it Blows the board. That was why they have gone to bigger Mosfets…..

Honestly …...In the end we will see, perhaps Marty will bring it back to the hill, even if the new board still has small Mosfets. What i wouldnt recommend. And when GW now starts to provide the bigger Mosfets on the 84V 1600Wh Version, too (as they allready do on the Nicola "Plus")...i guess  the Question will be also answered.

[maltocs]

48 minutes ago, TuN3M@N said:

But in addition have you found the fact sheets from US69 regarding the ESC board failures rates form the Z10? Still missing them.

Here is a thread and some stats by Jason, the largest supplier of wheels in the US.

[US69]

21 minutes ago, maltocs said:

Here is a thread and some stats by Jason, the largest supplier of wheels in the US.

Yip, and this thread is even pinned on top in the Ninebot section...so not that hard to find!...Some of the other pinned threats About common problems:

 

 

The Commons and exact board Problem, on all burned board at the same place:

https://www.facebook.com/groups/ninebotzseries/permalink/416438845606197/

 

 

 

Edited June 19, 2019 by US69

[Harold Farrenkopf]

4 minutes ago, US69 said:

Sure the film did all that, Yip, it reduced A BIT of the heat  removal and sure i accept your Job Evaluation. Perhaps then you should also accept the 4years experience here with the GW boards with that small Mosfets..

Dude, the film heat transfer resistance is not a bit. It is a very high thermal resistance. It is almost like not having it mounted to the aluminum heat sink at all and likely only survived this long because of the fan blowing air over them. 

As long as the mosfet can handle the current and has sufficient heat dissipation to keep the semiconductor junctions below a safe operating temperature, the style of case isn’t an issue. 

[US69]

5 minutes ago, Harold Farrenkopf said:

As long as the mosfet can handle the current and has sufficient heat dissipation to keep the semiconductor junctions below a safe operating temperature, the style of case isn’t an issue.

Yes, sure, then probably all the dozens of Mosfet Blows of the old Mosfet case have been due to insufficient heat dissipations…..

And Dude, thats excatly what i say...Gotway does not have any protections of amperage draw on it's wheels:Means in the end you will ALWAYS find a hill that will blow the Mosfets!

 

But to end this: You have your opinion….i have mine.

 

[LucasD]

Are those amperage reading accurate?

I see my Mten3 spike to 90-100A when doing pendulums...

[meepmeepmayer]

7 minutes ago, LucasD said:

Are those amperage reading accurate?

I would treat them as fantasy numbers coming somewhere out of the electronics. How much they have to do with reality is an unanswered question, and if they even matter is also a good question. They're only good for empirically comparing behavior between the same or similar wheels in various situations.

Also there's a huge difference between a spike (which may or may not be just a mathematical artifact in some way) and a continuous power draw and the associated current (a much more stable piece of information).

But in general, pendulums are extreme stress/heat, so don't overdo it