V12 Cutout tracking

[rcgldr]

5 hours ago, MegaObi said:

high power demand.

Try running EUC World to monitor peak power and peak current when doing this test. The numbers won't be that high. It's probably a high voltage | low current scenario, and most likely to fail when the motor is nearly stopped during a transition in direction. If the current | torque was as high as it would be when doing hard acceleration with the V12 plus rider, a person wouldn't be able to hold the V12 mostly in place when doing this test. There must be some sort of effective rotational acceleration limiter during a free spin test, maybe inherently limited by the way the circuit board controls the motor.

Edited January 9, 2022 by rcgldr

[Bikemike2777]

On 1/2/2022 at 3:54 AM, fbhb said:

Ecodrift's teardown shows that exact spec of mosfet, which they were also quite concerned about at the time of inspection, shown in this image/text of theirs quoted below:

Maybe this has been the main/sole reason behind the cause of All the recent issues with V12 cutout dramas!?

"The marking of the field-effect transistors is clearly visible. This is the Infineon IPP023N10N5. These are the same transistors that are on the V11 and V10F. Everything would be fine, but the V12 voltage is higher. And the denomination of 100V looks very suspicious here. And will the field workers withstand a voltage of, say, 110V under heavy braking? We really hope that Inmotion has calculated all this."

Do you think ordering higher voltage fets for all 12 positions would eliminate blowing fets?

[Bikemike2777]

Guys I don't have a v12 yet but I'm going to order 1 hopefully this week.  I'm no genius but I'm wondering if the balance of capacitors and voltage or amperage limits of fets.   I do work with X class drones with 12s lipo power source.  We tend to blow a lot of esc's when capacitors pop or don't control spikes.  So I'm not sure what caps these are equipped with but it might be a possible issue to consider looking into. 

[Paul g]

37 minutes ago, Bikemike2777 said:

Guys I don't have a v12 yet but I'm going to order 1 hopefully this week.  I'm no genius but I'm wondering if the balance of capacitors and voltage or amperage limits of fets.   I do work with X class drones with 12s lipo power source.  We tend to blow a lot of esc's when capacitors pop or don't control spikes.  So I'm not sure what caps these are equipped with but it might be a possible issue to consider looking into. 

   Don’t buy the V12, my advice. We all talk about issues with V12 here, don’t let yourself fooled by beautiful reviews on YouTube. That’s what I did. I see now that I was so blind all this time, a lot of people were saying that InMotion has had issue with underrated MOSFETs, or less MOSFETs than the other producers in the other wheels, and that their wheels lack good acceleration because of that. It’s like I’ve been blind. Someone in an early tear dawn even was surprised by the 100V MOSFETs on a 100V…Again I was blind.
   Only if InMotion issues a redesigned control board for the motor with proper MOSFETs consider buying it, otherwise make your self a service and buy something else.

[Paul g]

1 hour ago, Bikemike2777 said:

Do you think ordering higher voltage fets for all 12 positions would eliminate blowing fets?

There would be one candidate (IPP041N12N3 G) but:

- it is not the recommended 125V, yet better than the 100V that come from InMotion

- I think we would need a firmware update for them, because they have fall and rise times different than the IPP023N10N5, so it is no guarantee it would work with the firmware for IPP023N10N5, riding it with that firmware might be very dangerous, which is what we want to avoid in the first place. This has little chance to happen, because we would have two different firmwares for the same wheel, which would also be dangerous.
     What should happen is that InMotion should replace all boards having the IPP023N10N5 MOSFETs with boards having the IPP041N12N3  MOSFETs then release the proper firmware for them. That would be the most practical of all solutions right now.

   If InMotion wants to do an even righteous act, then they should redesign from ground up the heat sink and the board for proper 125V MOSFETs - which do not have a similar form factor, nor the same heat dissipation, with the ones used right now (see what @RagingGrandpa was saying about the 125V ones), and then send them as replacement while recalling all the V12 issued until now. That is the ideal thing. I don’t see it happening as it would not be practical. 
  The best thing, InMotion, please stop producing this model! It was a fail!

[supercurio]

@Richardo no new cutout incidents submitted or identified recently?

(At least a good news hopefully, catching the worst of these wheels with the stress test)

[supercurio]

32 minutes ago, Paul g said:

There would be one candidate (IPP041N12N3 G) but:

- it is not the recommended 125V, yet better than the 100V that come from InMotion

- I think we would need a firmware update for them, because they have fall and rise times different than the IPP023N10N5, so it is no guarantee it would work with the firmware for IPP023N10N5, riding it with that firmware might be very dangerous, which is what we want to avoid in the first place. This has little chance to happen, because we would have two different firmwares for the same wheel, which would also be dangerous.
     What should happen is that InMotion should replace all boards having the IPP023N10N5 MOSFETs with boards having the IPP041N12N3  MOSFETs then release the proper firmware for them. That would be the most practical of all solutions right now.

   If InMotion wants to do an even righteous act, then they should redesign from ground up the heat sink and the board for proper 125V MOSFETs - which do not have a similar form factor, nor the same heat dissipation, with the ones used right now (see what @RagingGrandpa was saying about the 125V ones), and then send them as replacement while recalling all the V12 issued until now. That is the ideal thing. I don’t see it happening as it would not be practical. 
  The best thing, InMotion, please stop producing this model! It was a fail!

Cool find, it looks like this 120V MOSFET gains a safe operating area in higher voltages, but loses with amount of current, power dissipation, and avalanche energy single pulses significantly.

So that could work, but with more than 12 of them.

[onizukagto]

6 hours ago, Paul g said:

There would be one candidate (IPP041N12N3 G) but:

- it is not the recommended 125V, yet better than the 100V that come from InMotion

- I think we would need a firmware update for them, because they have fall and rise times different than the IPP023N10N5, so it is no guarantee it would work with the firmware for IPP023N10N5, riding it with that firmware might be very dangerous, which is what we want to avoid in the first place. This has little chance to happen, because we would have two different firmwares for the same wheel, which would also be dangerous.
     What should happen is that InMotion should replace all boards having the IPP023N10N5 MOSFETs with boards having the IPP041N12N3  MOSFETs then release the proper firmware for them. That would be the most practical of all solutions right now.

   If InMotion wants to do an even righteous act, then they should redesign from ground up the heat sink and the board for proper 125V MOSFETs - which do not have a similar form factor, nor the same heat dissipation, with the ones used right now (see what @RagingGrandpa was saying about the 125V ones), and then send them as replacement while recalling all the V12 issued until now. That is the ideal thing. I don’t see it happening as it would not be practical. 
  The best thing, InMotion, please stop producing this model! It was a fail!

Can you please repeat this in gotway/Begode, Leperkim and knigsong forums?

This needs to be applied to all companies who have cutouts and explosions. Recall the faulty model and send replacements. Only way to restore any confident in any EUC model. 

 

In the mean time we should all just go back to 2017 model V10F. 

 

It's the only way to be safe. 

[UniVehje]

11 hours ago, Paul g said:

a lot of people were saying that InMotion has had issue with underrated MOSFETs, or less MOSFETs than the other producers in the other wheels, and that their wheels lack good acceleration because of that

Let's not spread bad info and speculation, ok? Acceleration has nothing to do with MOSFETs and so far I've only heard one model (V10) having too few MOSFETs and that might have caused them to overheat for heavier riders in uphills. Even that model had the same set of them as many others. 

[Steve Evans]

guys...

my V12 died the night i got it (batch 2, back in november) . it worked shortly for its maiden around the block. i got it home and it would not power on again. it might be this same issue with the mosfets.

i sent the wheel to ewheels & got it back 2 weeks later to find the serial number had changed (i guess they replaced the main board).

that new serial number is considerably LOWER than the original. so i am trying to figure out if my current board is subject to the mosfet failures since they are confined to batch 2 (ie is my board from batch 1?).

does anyone have a way of relating serial numbers to V12 batches?

thanks,

steve

 

[supercurio]

33 minutes ago, evans036 said:

that new serial number is considerably LOWER than the original. so i am trying to figure out if my current board is subject to the mosfet failures since they are confined to batch 2 (ie is my board from batch 1?).

Both cut-outs and stress test failures affect batch 1 as well.
The issue concerns all V12.

[Rawnei]

Doesn't seem to be any Batch 1 failures at least not in the spreadsheet which could confirm the bad batch of components for Batch 2 claim, my reseller just got the delivery of V12's mine included and will begin testing them before sending them out to customers.

[supercurio]

2 minutes ago, Rawnei said:

Doesn't seem to be any Batch 1 failures at least not in the spreadsheet which could confirm the bad batch of components for Batch 2 claim, my reseller just got the delivery of V12's mine included and will begin testing them before sending them out to customers.

Ah yes I checked again and there was no test failure recorded on Batch 1 specifically, however there were cut-out: see the various tabs in the cut-out spreadsheet. 

[rolis]

Alright. I start seeing, that we are going in circles here.
 

What we know officially from inmotion:

1. The issue is 100% MOSFETs.
2. That having higher rated MOSFETs would be positive

   Quote

   Theoretically it’s should be better to solder higher rated mosfet, but in reality there are a lot more to consider to make sure the selected model a good fit for the system, so we don’t recommend to do that at this moment - Cecily from Inmotion

3. Inmotions statement is that they changed the provider of MOSFETs and probably got a bad batch. 

 

What we know from the collected Data:

1. The batch of your wheel does not really matter. Neither does the battery level, firmware or mileage of the wheel.
   (note: there is nothing about batch1 in the dataset, but I think I have a few in the many messages I got. going to check it.)
2. 23% out of 70 Wheels have failed the test, meaning their wheel is not turning on anymore.
3. about 1/3 are not able to re-enact the test properly

 

Main Theories:

1. "grey market" MOSFETs because of the world-wide shortage
2. Using 100V (MAX) rated MOSFETs on 100V Wheel

 

My 5 cents:

Hello everybody again. I think that until Inmotion won´t tell us a detailed version of why their flagship wheel has a high failure rate (not only stress tests, but as simple as people not being able to turn the wheel on after charging), or an experienced engineer in electric motor drives having a look at the wheel with testing equipment and measuring what needs to be measured, we can not really say for sure what the exact problem is.
I have been quietly lurking on the forum and social media since september 2021, because that´s when I made the pre-purchase for the V12. I really liked its "quirks and features" (-Doug DeMuro), and of course Inmotions name as a high quality company (which I still think it is). After waiting for nearly half a year, I decided to cancel my order about 2-3 weeks before actually receiving the wheel because of the Data I have collected and the research I have done. I simply cannot buy a product with such a high failure rate. 

If anyone is interested in my opinion: I have to go for theory number two on why the wheels are failing. Its more or less an educated guess, but nothing to be taken too serious. I am a electrical engineering university student, but very far from knowing everything, if anything.

Very simplified: EUCs use a 3-Phase Motor.  An h-bridge is used to convert the DC voltage from the battery to 3-Phase AC voltage that is needed to spin the motor. It consists of 6 MOSFETs that act as 3 switches. The V12 has 12 of those components on the board and my guess is, that they are in parallel which enables higher current to be used (more torque). If you would put them in series, it would mean less current and more voltage (more speed), but that is pretty complicated. Thats why I am  disregarding this option. When you do the "test" or when you break very quickly, a voltage spike is created that goes though the system because EUCs do not use mechanical breaking, but regenerative braking. These Voltage spikes can be very dangerous to components but there are ways to limit them of course. I think that that is the problem. 100V were probably just enough on paper when designing the board with maybe a little margin, but we see, that in reality its different. Some MOSFETs survive the test, some will probably degrade faster because of them being used on the edge of their capabilities.

Either way, I wish Inmotion good luck in dealing with this problem and I hope that in future they will know to do even more stress tests on the components (on each and every wheel that goes out), which is normal practice to ensure the safety of their riders as they preach. I believe that they still can recover and be the "Quality" company that we were hoping for in this growing market.

Thank you for reading this

P.S.:I will be no longer adding test results to the list since it is more or less not giving us any new information.

P.P.S: Still thinking about "un-cancelling" my order on the v12

 

Edits: mostly grammar

Edited January 10, 2022 by rolis

[Unventor]

6 hours ago, evans036 said:

guys...

my V12 died the night i got it (batch 2, back in november) . it worked shortly for its maiden around the block. i got it home and it would not power on again. it might be this same issue with the mosfets.

i sent the wheel to ewheels & got it back 2 weeks later to find the serial number had changed (i guess they replaced the main board).

that new serial number is considerably LOWER than the original. so i am trying to figure out if my current board is subject to the mosfet failures since they are confined to batch 2 (ie is my board from batch 1?).

does anyone have a way of relating serial numbers to V12 batches?

thanks,

steve

 

Inmotion serial numbers are random, so sequence does not matter. 

The serial number is embedded in the main board. The drive board is the one that holds the mosfet to control the motor power (or how you would say it). 

Only Ewheel together with Inmotion can answer the iteration of the mounted boards. You might be able to spot a version nu. Ber on the boards. 

[Steve Evans]

2 hours ago, Unventor said:

Inmotion serial numbers are random, so sequence does not matter. 

The serial number is embedded in the main board. The drive board is the one that holds the mosfet to control the motor power (or how you would say it). 

Only Ewheel together with Inmotion can answer the iteration of the mounted boards. You might be able to spot a version nu. Ber on the boards. 

thanks much for clarification - i did not realize there is a main board (with the serial number) and a separate control board (with the mosfets). sorry for the noise everyone.

steve

 

[terlikaa]

Well.. There's already one wheel that passed the test and now, a week later, mosfets are blown. 

https://m.facebook.com/groups/inmotionv12/permalink/502406191191640/

[supercurio]

16 minutes ago, terlikaa said:

Well.. There's already one wheel that passed the test and now, a week later, mosfets are blown. 

https://m.facebook.com/groups/inmotionv12/permalink/502406191191640/

Thanks for sharing, I could not find the test as a video in the stats.
It's possible that the stress test was not executed perfectly, as many have difficulty to do so (easy to misunderstand the instructions, heavy object, requires precise timing etc)

[Paradox]

17 minutes ago, terlikaa said:

Well.. There's already one wheel that passed the test and now, a week later, mosfets are blown. 

Interesting his wheel powers on. 

[terlikaa]

4 minutes ago, Paradox said:

Interesting his wheel powers on.

When it's on charger only. 

 

Edited January 11, 2022 by terlikaa

[Planemo]

23 minutes ago, terlikaa said:

Well.. There's already one wheel that passed the test and now, a week later, mosfets are blown. 

Shocker. Who woulda thunk it!

And if the test wasn't done 'perfectly' then its another good reason for the test itself to be largely useless.

Some very brave souls indeed who are getting on V12's after this 'test'.

[Paul g]

10 minutes ago, terlikaa said:

Well.. There's already one wheel that passed the test and now, a week later, mosfets are blown. 

https://m.facebook.com/groups/inmotionv12/permalink/502406191191640/

InMotion solutions for the people. Don’t worry guys, InMotion is learning now how to build EUCs and maybe next one will be the one. What can you do? I now have a V12 that I won’t perform the recommended test on- it's mostly useless, we knew that, I will ride it like an old and crumbly bike at very low speed, geared from head to toe, and that will probably end up rusting in a corner somewhere because I’ll be forced to buy something else

[supercurio]

7 minutes ago, Planemo said:

Shocker. Who woulda thunk it!

And if the test wasn't done 'perfectly' then its another good reason for the test itself to be largely useless.

Some very brave souls indeed who are getting on V12's after this 'test'.

While I fully understand the snark here (well deserved), some people thought that the test was merely lifting the wheel and letting it free-spin.
One person did that and uploaded it on YouTube so commenters warned him about the problematic execution (and second test is not that much better unfortunately)

Knowing this is a possibility, what is the ratio of actually stress test vs nothing test, and car we tell if this report of later cut-out disqualifies the test entirely or not.

I gave some material with good and bad tests to the distributors where I and a few friends order a V12 from. He sent me a video with the best stress test I've seen so far, 4+ minutes long!
Hopefully, most distributors will do effective stress tests before sending out wheels, at least.

But doe it mean that the synthetic stress test is nothing compared to real-world stress or that this person couldn't reproduce the stress test as intended (and really, no blame here)?

Let's investigate.

Edited January 11, 2022 by supercurio

[Planemo]

I would deffo do the test, break that damn board. Do the test 100 times. Everything you can in order to screw that wheel right up. Then you will get another board

 

[Paul A]

Does getting another board solve the problem though?