S22 Motherboard Failures

[Tawpie]

I think it's time to start collecting information on motherboard failures—there have been more than a few now. I just covered the balance on my pre-order so mine is (still) in factory fresh condition but if your board has died, can you share your story? In particular, what conditions led to your board failure?

Personally, I'd like to start understanding what's going on. Hopefully it's teething pains, but there are rumors out of China of a "recall" and I'm led to believe eWheels has a not-insignificant number of replacement boards being air shipped so…

I have an upcoming a road trip and only have room for 1 wheel—whatever I bring, I need it to have a decent chance of working for a week, or at least have an idea of what to try to avoid.

Edited August 10, 2022 by Tawpie

[Rawnei]

Would also like to know, recall still a rumor, nothing confirmed by KS or resellers, opposite KS has only denied it so far, I heard a failure rate of 10% from one reseller, if true that's on par with many wheel launches.

 

[supercurio]

On the topic, although it's not an official recommendation by anybody, since there are mainboard failures I would recommend running the V12-style spin test before riding a new S22.

In worst case it will do nothing but possibly it will catch a future mainboard failure that would lead to a crash or being left stranded otherwise. My S22 passed just fine, yours should just as well!

Here's how:

 

[NSFW]

It's going to be hard to establish the numerator and denominator for the failure rate since not everyone who has an S22 is on the forum. But it's hard to take the denials seriously. There are too many failures to write them all off as isolated incidents.

Mine has symptoms of blown MOSFETs: doesn't turn on, wheel is hard to turn. I had it less than a month, put about 120 miles on it. 

[Miko.cz]

Friend's S22 board failure:

1. Product: serial batch KS-S22
2. Date: July 2022
3. Incident: power cut off
4. Source: MOSFET blown
5. Rider injury: light
6. Result: EUC unable to turn on
7. Fixed: motherboard replaced
8. Description:
   • Trail ride, one hour normal trail use (could be higher use for normal people) with pauses, total 10km.
   • Landing moment in jump - EUC suspension worked and in same moment EUC cutted off. Landing type position: light braking. Speed: about 25km/h.
   • Same was done about 20x without any problem.
   • Got EUC log with interrupted loggings (not in BT range). Last reading: Batt: 91%, Voltage: 122V, Current: -1.7A, Temp: 32/44/40°C (board/motor/batt).
   • No warning or any signature of incomming problem.
9. Update - possible reason (speculation): very low amount of heat transfering heat transfering paste

Edited August 13, 2022 by Miko.cz

[JerJer]

My S22 failed with less than 30km total travel on it. Traveling around a tight corner at low speed (less than 10km/per hour) it tipped on it's side (no beep, no warning) and wouldn't turn on again. At first I thought I had unbalanced the wheel by traveling so slowly around a tight bend on an unfamiliar wheel and dropped it  (not that something so insignificant should of caused such a failure) , but, then remembered there were no beeps usually associated with a tipping wheel, so, it must of blown before it hit the ground.

Waited ten/fifteen minutes, still wouldn't turn on, no app connection. The distributor suggested it was a mosfet failure as the wheel was resisting turning and suggested getting the wheel home and connecting it to the charger in the hope of (?) then being able to connect to the app and collect diagnostic information. I recommend not connecting the charger to an S22 in this state, as, there was no noticeable positive difference (the app still didn't connect) and once the motherboard was replaced and the wheel seemed to be working fine the charger no longer worked.

[buffs]

On 8/11/2022 at 4:53 PM, JerJer said:

My S22 failed with less than 30km total travel on it. Traveling around a tight corner at low speed (less than 10km/per hour) it tipped on it's side (no beep, no warning) and wouldn't turn on again. At first I thought I had unbalanced the wheel by traveling so slowly around a tight bend on an unfamiliar wheel and dropped it  (not that something so insignificant should of caused such a failure) , but, then remembered there were no beeps usually associated with a tipping wheel, so, it must of blown before it hit the ground.

Waited ten/fifteen minutes, still wouldn't turn on, no app connection. The distributor suggested it was a mosfet failure as the wheel was resisting turning and suggested getting the wheel home and connecting it to the charger in the hope of (?) then being able to connect to the app and collect diagnostic information. I recommend not connecting the charger to an S22 in this state, as, there was no noticeable positive difference (the app still didn't connect) and once the motherboard was replaced and the wheel seemed to be working fine the charger no longer worked.

Thanks for the information. Did you replace the board, or did the distributor? Do you know if it was the same board version or something updated?

Edited August 13, 2022 by buffs

[MexicanBatman]

One demo wheel fire and KS were everywhere assuring us they’d investigate blah blah

 

boards burning mosfet all over the place and not a peep from KS

 

not good enough!

 

if only I could take my money elsewhere, but everyone seems to be plagued with problems

Edited August 12, 2022 by Trevor Phillips

[onkeldanuel]

14 minutes ago, Trevor Phillips said:

 

if only I could take my money elsewhere, but everyone seems to be plagued with problems

This!

[JerJer]

18 hours ago, buffs said:

Thanks for the information. Did you replace the board, or did the distributor? Do you know if it was the same board version or something updated?

The distributor provided a new board. I think it was the same board version as the original board was ( they looked the same as one another).

[supercurio]

Not sure if relevant, since the root cause is the motor self-destructing, but the result is still a motherboard failure (doesn't turn on anymore)
More details here.

 

[onkeldanuel]

Your v12 style Stresstest was very rough few days ago and while i get the Intention i think such a stress like in this rocking back and forth without load multiple times will never happen at riding.....dont know but would guess this killed your motor

[supercurio]

@onkeldanuel the S22 is an off-road beast. Bonking and jumping over roots, with the motor spinning out until it catches grip again is fairly similar.
Then until recently, the majority of V12 passed the same test, none had their motor falling apart.

Problem is bad construction / QC, not testing.

[techyiam]

3 minutes ago, supercurio said:

@onkeldanuel the S22 is an off-road beast. Bonking and jumping over roots, with the motor spinning out until it catches grip again is fairly similar.
Then until recently, the majority of V12 passed the same test, none had their motor falling apart.

Problem is bad construction / QC, not testing.

Did @Rawnei perform the same stress test on his S22 as you?

[onkeldanuel]

12 minutes ago, supercurio said:

@onkeldanuel the S22 is an off-road beast. Bonking and jumping over roots, with the motor spinning out until it catches grip again is fairly similar.
Then until recently, the majority of V12 passed the same test, none had their motor falling apart.

Problem is bad construction / QC, not testing.

I understand this, but imagine 2 years ago it was common sense to better dont do a freespin topspeed test because you risk to blow up your wheel....then inmotion came up with this Stresstest and suddenly every wheel should be stresstested like this.....

Again i fully get it but only am i thinking that this is slightly over the top.....

One can do a freespin with hard braking and so on but this ultra rough rocking back and forth without load can randomly kill every wheel at some point perhaps

Edited August 14, 2022 by onkeldanuel

[supercurio]

8 minutes ago, techyiam said:

Did @Rawnei perform the same stress test on his S22 as you?

No

[Tawpie]

@supercurio ouch. Bad luck. The noise the motor was making was Trouble... it sounded like something was loose and it was only a matter of time until the motor jammed.

Curious... MOSFETs blew? If I were you I wouldn't try this but KSs will reset some "do not operate the motor" errors when you reconnect the charger. And I believe the firmware change made after the fire allowed for something to reset the BMS if it trips due to overcurrent/MOSFET short. I don't remember if it was as simple as connecting the charger or if it needed either the motor or battery to be disconnected first. I think it's in KS's investigation report.

But I would definitely disconnect the batteries, just in case.

I feel bad you're drawing some short straws recently. I would recommend delaying any skydiving until your luck takes a few turns for the better.

Edited August 14, 2022 by Tawpie

[supercurio]

9 minutes ago, Tawpie said:

Curious... MOSFETs blew? If I were you I wouldn't try this but KSs will reset some "do not operate the motor" errors when you reconnect the charger. And I believe the firmware change made after the fire allowed for something to reset the BMS if it trips due to overcurrent/MOSFET short. I don't remember if it was as simple as connecting the charger or if it needed either the motor or battery to be disconnected first. I think it's in KS's investigation report.

Yes MOSFETs are very blown. Rolling the wheel a couple meters is a real workout due to the high resistance.
I can't imagine the trouble if that happened in the middle of nowhere in a forest - carrying it would be required.

9 minutes ago, Tawpie said:

But I would definitely disconnect the batteries, just in case.

I feel bad you're drawing some short straws recently. I would recommend delaying any skydiving until your luck takes a few turns for the better.

Yes will disconnect the batteries, who knows the BMS is in right now. Also: no fire!
Definitely better than the NYC incident. I'll check if the BMS fuses blew or the software one worked.

About flying.. time to go back to known reliable wheels I guess.

[buffs]

I have 100 miles on my S22 and haven't noticed any issue related to the control board, but I'm concerned about the reported failures/cutoffs. Is there a time or distance where you could reasonably think that the board is good, or will it always be a time bomb? I've asked my distributor about getting a replacement, and they will provide me with a "more robust" controller at cost. There is no recall from KS at this time and there may never be.  Would you stay with the OG board or pay for the updated controller?

Edited August 17, 2022 by buffs

[Tawpie]

48 minutes ago, buffs said:

Would you stay with the OG board or pay for the updated controller?

It sort of depends... what is more robust about this new controller? How much does it cost? Is there really a new controller? I'd ask for the part marking on the 'new' one just to be sure you're really getting something different.

It does seem that the failures have been the kind that haven't caused anyone to get badly hurt, so I guess that could be some comfort. On the other hand, so far your's isn't broke—why fix it? If it does break, your distributor would replace it on warranty anyway so unless you want to try to buy peace of mind…

 

[supercurio]

1 hour ago, buffs said:

 and they will provide me with a "more robust" controller at cost

Although there are expectations of a new controller revision being tested at the moment in China, the "more robust" controller is still a theory at this point. I would not recommend to order or pay for anything at the moment, until confirmed that it exists, understand the differences if any and have view on the tradeoffs if brings.

Some users should get a replacement board within a few days and will look for differences. We'll share the details here. Then we will all start to get a better sense of what's up with that.

 

At the same time, I can't blame you for hoping for something better as someone just crashed due to burned MOSFET, and got hurt while riding on a 100km-old S22.

A little early to buy a board still, but I can't recommend enough the V12-style spin stress test.

Edited August 17, 2022 by supercurio

[meepmeepmayer]

The saga of the S22 is depressing. Such a nice wheel... and then such crazy problems

On 8/14/2022 at 9:33 PM, onkeldanuel said:

Your v12 style Stresstest was very rough few days ago and while i get the Intention i think such a stress like in this rocking back and forth without load multiple times will never happen at riding.....dont know but would guess this killed your motor

This test is like doing pendulums, with less load but much faster. It just stresses the electronics, so they would fry if they are weak/compromised. Doesn't have anything to do with real riding conditions. And I think healthy electronics should easily survive such a test. At worst the wheel should overheat and throw a warning for that.

[techyiam]

1 hour ago, supercurio said:

I can't recommend enough the V12-style spin stress test.

I don't follow your logic.

I can understand if everyone who performed and passed your recommended V12-style stress test on their S22 don't subsequently cutout in the field. Then it would make some sense to perform this test. But this isn't the case.

You are the only person who performed this test. It passed the first time. But at a later date, when you performed the test again, it promptly killed your board.

You haven't demonstrated this is a valid test in any capacity. 

Additionally, this is not an official test from Kingsong.

Edited August 17, 2022 by techyiam

[buffs]

1 hour ago, Tawpie said:

It sort of depends... what is more robust about this new controller? How much does it cost? Is there really a new controller?

I have no details other than what the distributor told me: "we have communicated these concerns to King Song, and King Song has updated the controller hardware to be more robust."

This implies to me there is updated hardware. Has anyone received a version 2 board?

The cost is $150, and if KS eventually does a recall they will refund.

There was another cutout reported today, and I'm trying to do anything to avoid that. We know the OG board has issues. We have no idea if the "new" board is any better. That's my dilemma.

[Tawpie]

24 minutes ago, techyiam said:

when you performed the test again, it promptly killed your board.

Kind of different circumstances though. The second test was not really the stress test, he was trying to get video of the motor noise by free spinning it. Not that I find any comfort at all in that.

Edited August 18, 2022 by Tawpie