meepmeepmayer

They do? That's good, I only heard about BMS firmware fixes. The S20/S22 mosfets are probably fine, no problem yet showed where the TO-247 size was too small. The V12 is rumored to get a new board with TO-247 sized mosfets right? That should fix these board failures.

I never realized how much extra mechanical stuff a suspension adds to a EUC. Without suspension, it's literally just the motor turning, that's the only mechanical movement. Now we have sliders and the suspension levers and whatnot...

I know this is just a joke, but I feel compelled to say this: Inmotion had a (sadly, predictably) bad board design (MOSFETs just too small) with the V12, but it looks like they are doing the only sensible thing and are making the hardware changes that can be fully expected to reliably fix the issue. And there were "only" board failures, no battery fires. KS had a novel catastrophic battery fire in addition to the board failure, and are proposing to "fix" the issue with a software update and nothing else. Quite different situations. In fact this makes the (awful enough) V12 issue look good in comparison.

Quick, which is better?! A software "fix" (that's what we have to believe, that it fixes... everything!) A fuse or something somewhere that any electrical amateur can confirm to prevent this, guaranteed, with no ambiguity or uncertainty Not sure what a qualified opinion of their solution is. But my unqualified opinion: I sure am not overly enthusiastic.

Just for reference, what is the actual tire diameter (as measured with a ruler) of the S22? Renaming this wheel is both surprisingly understandable and pathetic. And wheel names, supposedly named after tire sizes, are even more meaningless now.

We don't necessarily need to have megathreads. In fact, the less megathreads, the better. In can be just another forum without extra structure (which also is less work for the mods). There is a bit of overlap with the "Which electric unicycle to get?" where people might naturally ask where to buy in the same thread where they asked which EUC to get (which is perfectly fine!). But we want to keep that forum as it is, as it works very well like this.

Basically the point of the new forum would be: Finding a seller Discussing your seller experiences

Damn, you're right! The battery boxes seem to be a bad idea. Foil packs tend to only have a few cells burn.

Siehe hier:

Given by the like-soft-mode behavior of the S20 that @U-Stridefelt before it died, we can assume a board capacitor was broken. So the board failing first seems likely? Again, not an excuse for the battery to blow up, but it still happened.

The big issue is that any board failure should never never never be able to do anything to the battery, and a fuse or some other protection mechanism must kick in. That's a board-unrelated problem with the design of the battery packs and how they are connected to the rest of the wheel. The battery was possibly shorted for the ~25 seconds between the board popping and the start of the fire. That is a long time for no protection to happen. No fuse? No BMS shutdown? - Assuming the board caused the battery to go up and not the other way round. In that case, the board was collateral damage and something is seriously wrong with the battery. No matter what the (here assumed to be working) board does, like sending regen current to the packs or whatever, the battery should protect itself. - So either way, what was wrong with the battery?

On a lighter note, the timing of the scooter guy in the background in @Hsiang's video couldn't be more slapstick-worthy He comes riding along and stops at the light, looks at the S20 lying there, probably going "Huh what's this?", and right then the wheel starts spewing fire. His reaction is pretty good. (Timecoded at 10:09)

I meant the structure inside the motor (what you see when you take the motor side caps off), if I wasn't clear. I stand corrected. Here's a picture from EcoDrift's latest S20 disassembly. Pretty thin and light already! Guess that means the weight can't be fixed by one thing, but by reducing the weight of everything, if possible.

Sounds to me either the board failed and shorted the battery for a loooong time (which should not be possible flat-out) till the fire started, or the battery pack was compromised and some small input from the board (or the crash? Direct impact on battery box?) made it short itself.

Wow that is one spectacular fire. King Song S20 Eagle Flamethrower. Imagine if that had been indoors! Also props to the camera guy for keeping the camera pointed.

This topic was in "Commercial Advertisements", I moved it over to "Private Sales". Good luck (if you haven't sold it yet).

I'd take a Tesla over a 16S. More power and speed. The V10F also exists.

When the wheel goes its own way, best to let it do its thing and save yourself. You tend to hurt yourself when you prioritize the wheel. My shins certainly can confirm, and we had people hurting their knee nastily and whatnot from trying to catch a wheel instead of cooly running off and letting it tumble alone. So unless it is heading straight for water or some other person, no need to get involved, it is going to fall over soon anyways.

I believe it is electrical arcing inside the motor coils. Sounds like it at least, a bit like a campfire.

I always wondered if the steel supporting structure of the motors needs to be that heavy.

No. The answer is no. When people stress about keeping a fully charged battery, remember that Marty always says that he keeps his wheels at 100% and may not use them for a long while, and never noticed a thing.

Be careful, if the cells are really way under normal voltage, I believe that would permanently damage them.

Hadn't expected that. You were unlucky, but no other brand or model would have helped. All EUCs are amateur level China crap with laughable quality control if you have "Western" expectations. The good thing is, once you have a working wheel, it is going to be a working wheel forever. There are so few parts, and no wear except for the tire. Just some riders (like you) have to go through this discouraging bump right at the beginning, when a wheel is defective or fails right at the start due to lack of QC. But now you are over the bump (hopefully) and the good times will start soon (once you get your replacement)!

Oh no! Not like these guys don't have enough problems already...

You can't have a bad cell, because then your voltage would max out at 79.8V, and you are way above that. So it's certainly not that. I'm on the side of "don't worry too much and see what happens". But it can never hurt to ask your seller if he has any input on that.