Kingsong s20 Cut out FIRE (New York)

[supercurio]

1 minute ago, FlyboyEUC said:

My experience from seeing multiple mother boards blow on wheels (mostly Shermans) the popping sounds in the beginning sounds exactly like all the boards I've heard blow. There isn't much of a show other than quick flashes and smoke. I believe the board failed, then the batteries shorted.

The Shermans have fuses between the batteries and the board. The intent was to prevent the batteries from over charging the board but I think it serves better at preventing battery fires after the board blows.

Agree it sounds and even moves like a Sherman board burning, as shown here:

However the main difference with the S20 are explosions and flashes coming out via the little holes in the board compartment near the heatsink.

On the S20, the whole top cover is translucent and then there's the light reflector on the back, which you can see light blue very briefly.
That's why my guess is that these explosions are not coming from the mainboard otherwise we would see some amount of light coming through. even if the MOSFET are at the bottom of the board against the heatsink (like on Sherman)

But you might be right, and it could be the new firmware destroying a MOSFET when braking, and then failing to contain that so the whole board, then battery(ies) burn in a chain reaction.

Sadly it'll be hard to tell for us, but maybe it's not Kingsong first and they might already know too well what happened here.

[Tawpie]

eevee's? Their wheels, particularly "Haggred" had been through the wringer. Well, I don't know if they wrung it out after the LA rainstorm or not but at least one of their wheels got "rather drenched".

Hmmmm. Oddly, that makes me feel better. Sort of. Not much better actually, but I can avoid drenchings.

Edited March 27, 2022 by Tawpie

[supercurio]

Not eevee's I read from multiple sources that it's eWheels and that @Jason McNeil is on the case already.

[mhpr262]

Holy f***ing shit! That thing is like a flame thrower! If that happened in a passenger car, with the wheel in the rear passenger footwell like I always transport my wheels, all passengers in the car might suffer lethal burns and/or lethal smoke poisoning before the car could be brought to a stop! This is genuinely scary.

[mhpr262]

How many S20 are available? We should priority ship them to the Ukrainians and have them drop the wheels on some Russian convoys.

[supercurio]

I must say that the concensus, just like @FlyboyEUC wrote is that the mainboard failed, caught fire, which either physically propagated to the battery compartment(s), or shorted the battery pack(s), which instead of disconnecting via a SMD or solid state fuse, did not and led to igniting cells on fire.

An incredible amount of current, therefore very low resistance wire, which wouldn't itself burn off is required to set a cell on fire so that seems less likely than the fire physically propagating from the mainboard to the packs in that case.

Alas, the wheel was not updated to the latest firmware, so it's not the cause (confirmed by Hsiang, holder of this demo wheel for eWheels)

Which is frankly more concerning, since there's currently no good reason.

I must admit I liked the corrosion theory better because it seems easier to solve with waterproofing.

So what does that mean now: 150V rated MOSFETs not enough for a 126V wheel, failing after a couple months of riding?

Edited March 27, 2022 by supercurio

[Begodecrashtestdummy]

[Roadpower]

5 minutes ago, supercurio said:

So what does that mean now: 150V rated MOSFETs not enough for a 126V wheel, failing after a couple months of riding?

Assuming this is correct I would speculate an insufficient amount of overhead to cope with spikes or an over rated component, however I'm not an electrical engineer. Anyway this is all very speculative, I will trust for now that Kingsong will be highly motivated to get this under control. On another note looking at the flames blasting out of the wheel causes me to wonder if going above 100v for this battery type is just in general a bad idea for all the lurking energy within such a system.

[supercurio]

The biggest disappointment for me in this is that the S20 mainboard is capable of catching fire when failing.

Despite all its faults, the V12 mainboard never caught fire with countless burned MOSFETs. But when that happened you had to use a multimeter to identify which needed to be replaced, everything seemed intact.
I expected the same type of protection from Kingsong Electronics and firmware, in order for a component failure to not escalate to a mainboard fire.

Then a mainboard fire escalating to one, then both battery packs is the icing on the cake really.
@enaon developed on Telegram how the lack of isolation between mainboard and both packs could lead to everything on fire. A huge design fail for safety IMO.
And as a result the first S20 we see failing ends up in destroying the whole wheel, instead of one capacitor or a couple MOSFET to replace.

Edited March 27, 2022 by supercurio

[Tawpie]

We can only speculate... once anything goes kablooie all bets are off because in addition to adding stress to places it wasn't planned for, it introduces molten solder, bits of parts blasted everywhere they're not supposed to be, ionization paths, the list goes on. Although I would surely like to see the fault isolated to 1 subsystem and not cascade to others. That definitely should be improved.

[AndyBill]

Wow, that does not give one a lot of confidence in the relative safety of KingSong's engineering prowess, to say the least.

[.....]

6 hours ago, Finn Bjerke said:

 

Fourth of July version, nothing to see here....

Fwiw, if I were an insurance company or fire department, this kind of thing would definitely add some pages to the policy and increase rates. And people think a little 9mm pistol is dangerous....hahaha

Just remember kids, you are NOT allowed to EVER drop the wheel and you have to ride on a planet that isnt covered in water and rains. Not a big deal tho, just minor details. At least you can say you have the newest and most badass suspension unicycle thats ever doubled as a roman candle.

Edited March 27, 2022 by ShanesPlanet

[Paul A]

From the comments of the YouTube video.

Paul Stallone posted the video.

 

Paul Stallone

1 hour ago

 

Well the wheel was set out to NYC YouTube creator Hisang and he has released a couple of Videos on his channel you can search more there.

He rode this wheel for several weeks.

He did have a decent crash when a delivery guy on a bike stepped out in front of him.

Took a good spill at around 30mph and the wheel still worked.

 

I got it in my possession a couple days after that and waited for a couple days for the weather to cooperate so I can use it in the trails I usually ride my other Kingsong S18. I did about 5 miles and had no issues no spills and ran perfectly fine.

The wheel also had a demo day in NYC in early March or late February..

Nobody crashed it and I did see a couple people drop it at 1mph.. it is a top heavy wheel.. some ppl are not use to it so it went down.

Nothing out of the ordinary.

 

No details if anyone rode it in major rain but I believe it wasn't.

There's another wheel out west that got dropped in a fountain while attempting to ride on a ledge.

That wheel to my knowledge turned off but did not go on fire.

This wheel is a new 126v design the first of its kind.

All wheels till this point are 84v/100v and there are 4 major manufacturers.

 

Begode (formally called Gotway) , Inmotion, Leaperkim (Veteran Sherman) and this company that makes this wheel Kingsong.

[RayRay]

2 hours ago, mhpr262 said:

Holy f***ing shit! That thing is like a flame thrower! If that happened in a passenger car, with the wheel in the rear passenger footwell like I always transport my wheels, all passengers in the car might suffer lethal burns and/or lethal smoke poisoning before the car could be brought to a stop! This is genuinely scary.

Makes you think... Don't it?

Bad luck if it ignites gas tank and explodes. (As we say in SoCal : "no es bueno".)

[Paul A]

Appears the aluminum battery cases worked.

There didn't appear to be any ejecting cells.

The shooting flames were mainly confined to the one direction......in relation to the wheel, the flames shot out from base to top.

 

From crash/popping noise to initial smoke was approximately 20 seconds.

First main burst was approximately 25 seconds.

Second main burst was approximately 5 seconds.

Approximately 45 seconds of flame throwing.

 

[techyiam]

5 hours ago, supercurio said:

Observations

• Despite intense explosions, no light flash shows through the translucent cover (around the display) nor the light diffuser (at the rear)

Slow down the playback speed to 0.25. Around 0:17 .  There is a flash that can seen through the taillight diffuser. 

 

[BKW]

Come on guys, that's just the new S20 special feature...

[Paul A]

A demo wheel used by multiple NYCers', (unsupervised?), who have not paid for it, who don't need to care about paying for any repairs/damages...

Is there any other unknown/unreported crashes, damage, abuse etc.. from other NYC riders that had use of the wheel prior?

[Begodecrashtestdummy]

 

9 minutes ago, Paul A said:

A demo wheel used by multiple NYCers', (unsupervised?), who have not paid for it, who don't need to care about paying for any repairs/damages...

Is there any other unknown/unreported crashes, damage, abuse etc.. from other NYC riders that had use of the wheel prior?

This wheel was crashed at 25-30 mph If I remember correctly ??…a delivery driver pulled out in front of him like a week or so ago .I’m gunna have to go back and watch that crash again.not sure now I think it might have been a v11 he crashed 

Edited March 27, 2022 by Dosingpsychedelics

[Forwardnbak]

Even if due to a prior fall, surely this SHOULD NOT cause a fire, especially with an off-road inspired wheel.

 

[Paul A]

Yes, the YouTuber stated in the comments that Hsiang had a decent crash at around 30mph, when a delivery guy on a bike stepped out in front of him.

There is video of that crash?

[supercurio]

7 minutes ago, Paul A said:

A demo wheel used by multiple NYCers', (unsupervised?), who have not paid for it, who don't need to care about paying for any repairs/damages...

Is there any other unknown/unreported crashes, damage, abuse etc.. from other NYC riders that had use of the wheel prior?

I think it does not matter at all, a baseless anti-NYC bias would cripple not improve the assessment of this incident.
Reportedly, the wheel had 1 accidental crash at 30 mph in history and was not ridden in the rain (will probably be confirmed in @Hsiang's video)

The only bad practice that would count would be riding in very heavy rain and putting it in a car trunk or laid down on its side, and it doesn't seem to be the case.
Many wheels are ridden hard (and the rider might not even realize it if it rides effortlessly) and almost all crashed once in a while.

It would be a mistake for anybody to think that: "Oh yeah it's because it was ridden in NYC, so mine will be just fine".
There's no valid justification for this wheel catching fire.

[supercurio]

1 hour ago, techyiam said:

Slow down the playback speed to 0.25. Around 0:17 .  There is a flash that can seen through the taillight diffuser. 

Right, I noticed it too but since it appeared blue I thought it was a LED being lit accidentally in the process.
Maybe a wrong assumption, it could be arcing also, good point.

Edited March 27, 2022 by supercurio

[Paul A]

Not meant to be anti NYC bias, merely stating who the riders were.

 

A fall shouldn't cause a fire.

Do not know the extent of the damage from that crash.

 

[RagingGrandpa]

11 hours ago, supercurio said:

The S20 packs are fused. At 2x60A

Right. And all modern KS packs before S20 are internally fused.

But 60A per 2 cells sounds like overfusing! 

If we're talking about compact melting fuses, they can pass 2x rating for 1 second. It's 60A per cell, a huge torture.

To be fair, starting with very cold M50T cells, my pack survived 1 second at 80A per cell without burning... but perhaps this new M50LT pack was already warmed up from lots of fast riding? 

Anyway, I'd like to see a fuse rating near 30A (like Sherm). Not double.

 

Edited March 27, 2022 by RagingGrandpa