How worry are you about your EUC's going up in flames?

[Glock43x]

After reading a few threads on here (esp the one regarding storage), it seems like many are worry about it. Assuming batteries are not damaged or wet and not charging, is it possible for it to just randomly spontaneously combust?  I live in an apartment and  I own 2 16S's and 1 16X. I'm a bit paranoid now lol. Kept thinking.....go to work and come back to a burned apartment building. lol.

[0000]

I'd say you are right to be aware that apartment dwelling in general has been getting increasingly more hazardous to live in due to the growing adoption of PEVs (not the only reason, but I'll stay on topic ). Think about your average citizen and how much (or little) care they put into PEV selection, use and abuse, charging practices, and safe storage, and then proceed to weep for humanity. Can't really put a number on the increased risk, but it's definitely a non-zero number.

The way I think about it PEV batteries, especially as someone who frequently offroads my wheel, I think about all that impact and shock traveling up through the tire into the main structure, transferred to the battery assembly and cell holders, and then some non-zero damped impulses/vibrations imparted to each of the hundreds of spot welds and cell interconnects. Is there a good amount of damping to reduce these repeated impulses? Is there any rubbing occurring that I can't see without a full disassembly? Were the all the spot welds and solder connections made clean and solid?

There isn't much distance between the negative (case) and the positive electrode on each cell and it wouldn't take much mechanical failure of a nickel strip interconnect over hundreds or thousands of good vibration(al) miles somewhere in the battery assembly to accidentally get a battery to pop off IF things aren't right. That said, an EUC or PEV with internal quality issues or damage probably isn't going to spontaneously combust just sitting there in isolation without some kind of input.

Yeah man, I'd say if you're not at least a little bit paranoid living in close proximity to people who most likely don't put the same level of thought or care into their PEV interactions, you're probably not paying attention.

TLDR; I think PEVs and apartment-dwelling is a significant unstated risk that is set to continue increasing probably until things come to a head through some accumulation of fires and deaths.

Edited August 19, 2022 by Vanturion

[Tawpie]

4 hours ago, Glock43x said:

is it possible for it to just randomly spontaneously combust?

Yes. (see below)

BUT

Especially for the 16S and 16X, such events are exceptionally rare, I haven't heard of any but there are surely a handful. So I wouldn't be worried, but to be prudent you should not store your wheels near other flammables, and definitely do not store them anywhere that a fire might impede a fast exit from your apartment. Videos of battery fires (there are gobs, mostly out of CN) will scare the poopoo out of you, the take away should be that when these things do go up you want to be able to get out very quickly.

A Firesak would slow things down and may contain any fire enough to keep it from spreading and give you time to evacuate. They're expensive but may be a worthy investment. If they're too spendy, make room and get a metal garbage can and invert it over your wheels (one wheel per can!)—that should help keep a fire contained and buy time to get out. Maybe pickup a few concrete paving stones from Home Depot as a base.

____________________________________

Why yes? Spontaneous fire can result anytime any battery cell in your pack is critically damaged. Corrosion and water can cause this sort of damage, as can vibration and impact. However, improper charging is the worst enemy—watch the video the @mrelwood made to learn the proper charging protocol, including why it's important (search the forum for 80% charging video).

To reduce your risk, always follow good charging practice... you don't need to charge every time you ride (I wait until the wheel is below 50%), but when you do charge, charge to green light on the charger + 1-2 hours. This will support long term battery health. Then check the voltage with an app.

It's imperative to monitor the battery voltage (not %) when a charge cycle is complete, you want to know when things change because changes can be hints that your pack is getting unhappy. If the charger doesn't get your 16X to 82.5V, preferably >83V, your pack may be in trouble and I would be seriously looking at replacing it. Continuing to use a pack that doesn't charge all the way can accelerate battery degradation, especially if you ride aggressively and more so if you ride aggressively at charge levels below 40%. Packs that are degraded or just plain faulty are increasingly more likely to burst into flames as they get worse.

But as long as your batteries charge to >83V, there's really no extra reason for concern.

Still, make no mistake. These things contain a lot of energy (quart of gasoline?) and if the phase of the moon is wrong and you have an especially bad bout of terrible luck—they can spontaneously combust. It's rare, but it's possible. I recommend prudence, and careful monitoring.

Edited August 19, 2022 by Tawpie

[Funky]

I'm also paranoid, when i'm leaving my house and euc stays behind, without anyone else in house. (I live in 3 room apartment.) If fire started, it should not spread to neighbors, because we got good old concrete/brick walls. But anyways, i don't want to lose about 10-30k$ in damage.

So i bought euc sized metal closet 1.5mm thick walls and insulated it's inside with rockwool. And put it on some bricks, so if fire starts the flames will be at least contained. (When i finish building it, i will make a post.. Need to finish the doors still.) Spent around 200$ for this setup. Yeah i will still have smoke damage, but at least nothing will burn down.  

Doh thing going up in flames are very low, but still it can happen. So better be safe, than sorry. (Also 200$ for somewhat calmer mind is worth it.)

2 hours ago, Tawpie said:

 

It's imperative to monitor the battery voltage (not %) when a charge cycle is complete, you want to know when things change because changes can be hints that your pack is getting unhappy. If the charger doesn't get your 16X to 82.5V, preferably >83V, your pack may be in trouble and I would be seriously looking at replacing it. Continuing to use a pack that doesn't charge all the way can accelerate battery degradation, especially if you ride aggressively and more so if you ride aggressively at charge levels below 40%. Packs that are degraded or just plain faulty are increasingly more likely to burst into flames as they get worse.

But as long as your batteries charge to >83V, there's really no extra reason for concern.

Still, make no mistake. These things contain a lot of energy (quart of gasoline?) and if the phase of the moon is wrong and you have an especially bad bout of terrible luck—they can spontaneously combust. It's rare, but it's possible. I recommend prudence, and careful monitoring.

Doh battery capacity goes down over time. I at start had 84.5V and after 600km ridden, it's now at 84.3V normally. At some point it may go 81V (after 3-5 years.) You just need to check that it doesn't happen suddenly. Like last week was 84.3V next charge it's at 79.3V. If it drops suddenly down by 4.2V then you know one battery have "died". And you have a problem..

Edited August 19, 2022 by Funky

[mrelwood]

Educated posts above. But: I haven't seen any reported 16S, 16X, 18L or 18XL fires. And each of the mentioned models have sold many many thousands of units around the world for several years. So there probability of your's bursting in flames without a single warning sign would probably be much less than 0.0001%.

[Begodecrashtestdummy]

20 hours ago, Glock43x said:

After reading a few threads on here (esp the one regarding storage), it seems like many are worry about it. Assuming batteries are not damaged or wet and not charging, is it possible for it to just randomly spontaneously combust?  I live in an apartment and  I own 2 16S's and 1 16X. I'm a bit paranoid now lol. Kept thinking.....go to work and come back to a burned apartment building. lol.

It’s really not a problem if you have renters insurance or if all your neighbors are assholes 🤣🤣🤣

[Funky]

I really could have saved those 200$.. I have had the wheel almost a year and it has been sitting near my bed. But still, it was worth the calm head/heart, leaving the wheel behind. Without anybody home. Sure i got now a big box sitting where my wheel was.. And i'm okay with that.  

[wehey]

You’ll be fine…..it’s not a gotway 😀

[Wolverine]

If you have an electric unicycle from any manufacturer other than Gotway, you are fine and don't need to worry. There have been so many Gotway fires over the past few weeks that I've lost track of these events. People consciously take a risk when buying a Gotway electric unicycle and that is sad, very sad. Luckily, you don't have to worry.

However, if you are still concerned, I recommend getting a product called FireSak:

https://firesak.com/

 

 

[plentora]

21 minutes ago, Wolverine said:

If you have an electric unicycle from any manufacturer other than Gotway, you are fine and don't need to worry. There have been so many Gotway fires over the past few weeks that I've lost track of these events. People consciously take a risk when buying a Gotway electric unicycle and that is sad, very sad. Luckily, you don't have to worry.

What I've understood Gotway batteries are pretty much same as other batteries, same passive/blind BMS (which isn't really BMS, just a overvoltage discharging). Same as in almost all manufacturers have at the moment.

So the difference is they use wrong cells for the use and let riders overload the cells 2-3x of maximum rated capacity? Gotways are powerful and fast but it is just because they overload the cells very hard - basically let you destroy the cells and make the batteries ticking bomb?

 

[Funky]

2 hours ago, Wolverine said:

If you have an electric unicycle from any manufacturer other than Gotway, you are fine and don't need to worry. There have been so many Gotway fires over the past few weeks that I've lost track of these events. People consciously take a risk when buying a Gotway electric unicycle and that is sad, very sad. Luckily, you don't have to worry.

However, if you are still concerned, I recommend getting a product called FireSak:

https://firesak.com/

 

 

 

 

 

I would better buy a so called "metal box" and DIY it to my needs. You still need to place some bricks or something under that "sak" same way for "metal box". So ground doesn't catch on fire. If you place it on concrete floor then it's okey..

https://www.se.com/ww/en/product/NSYCRN86300P/spacial-crn-plain-door-with-mount-plate-h800xw600xd300-ip66-ik10-ral7035-/

[quickbot]

On 8/19/2022 at 5:06 AM, Glock43x said:

After reading a few threads on here (esp the one regarding storage), it seems like many are worry about it. Assuming batteries are not damaged or wet and not charging, is it possible for it to just randomly spontaneously combust?  I live in an apartment and  I own 2 16S's and 1 16X. I'm a bit paranoid now lol. Kept thinking.....go to work and come back to a burned apartment building. lol.

It was enough when i started to vape 14years ago and was reading everything about li ion batts...i was shocked.  You never know, it can go up in flames, it can bloat up etc.... i bought blinker light for my bicycle...cheap one. One day i was cleaning my shelf and that light was cracked open and battery inside was 3x larger...it was pretty much luck it didnt catch fire. So im sure, no matter what and how carefully you treat them, there is still a percent chance for trouble.   Euc is new and hanvt charged it yet...vet sherman max, but have scoiter for twovyears, that i charge daily to max from about 40% abd all is fine even tho i should go to someone who can check pack as it went down from 67v when i bought(had to be 67.2V to 66.4 -66.6V fully charged now. I hope its only bad batts not a single batt going dead.

[Funky]

1 hour ago, quickbot said:

but have scoiter for twovyears, that i charge daily to max from about 40% abd all is fine even tho i should go to someone who can check pack as it went down from 67v when i bought(had to be 67.2V to 66.4 -66.6V fully charged now. I hope its only bad batts not a single batt going dead.

Should be fine. 1 battery is 4.2V. Meaning if battery suddenly dies, instead of 67.2V it would show as ~63V at full charge.

66.4-66.6v is normal if you charge it everyday..

Your battery pack loses it "max" capacity over time/use. If you originally had 67.2V, after 500-1000km ridden it will be ~66.8V After more ~1000km it will be ~66.4V So on...

If it drops down by 4.2V suddenly -  then you got problem. Slowly losing 00.1V over 300-600km is okey. Losing 4.2V suddenly - very bad.

 

My 18xl at start had 84.5V, after 600km ridden it's now charges to 84.3V - i lost 00.2V.

Edited August 21, 2022 by Funky

[mrelwood]

 

3 hours ago, Funky said:

Your battery pack loses it "max" capacity over time/use. If you originally had 67.2V, after 500-1000km ridden it will be ~66.8V After more ~1000km it will be ~66.4V So on...

Losing max capacity is different from losing max voltage. It should still charge up to nearly the same as before. My MSX had 14000km on if when I sold it, and it charged up to the same 83.4V it did when it was new.

But like you said, sudden drops are the ones to worry about.

 

[Begodecrashtestdummy]

Definitely losing confidence in quality of euc’s .replaced dc converter at 2 months of buying it new ….now the capacitors blew And scorched the main board at around 4 months …sent ewheels an email just waiting to hear back from them but yes I’m becoming worried that eventually my wheel will burst into flames .

[mrelwood]

2 minutes ago, Dosingpsychedelics said:

Definitely losing confidence in quality of euc’s .replaced dc converter at 2 months of buying it new ….now the capacitors blew And scorched the main board at around 4 months

Which wheel is that?

It has seemed already before that repairing EUC mainboards is not recommended. If they break at one spot, usually the fault is not in that specific spot, but that it's a more widespread problem that can then manifest itself somewhere else. New boards cost a few bills, and tend to be worth it.

[Funky]

My guess Gotway wheel.

And you are surprised about quality.  Go buy something "better". If RS had better quality, i also would love it.. But at less, we don't live in perfect world.

Edited August 21, 2022 by Funky

[Begodecrashtestdummy]

1 hour ago, mrelwood said:

Which wheel is that?

It has seemed already before that repairing EUC mainboards is not recommended. If they break at one spot, usually the fault is not in that specific spot, but that it's a more widespread problem that can then manifest itself somewhere else. New boards cost a few bills, and tend to be worth it.

The dc converter is small seperate board from the main board now on the rs19 they split them up .

[Funky]

3 hours ago, mrelwood said:

 

Losing max capacity is different from losing max voltage.

 

How is it different? The max voltage decreases over time. Meaning the capacity goes "lower" by 0.001% or so. (You won't feel it in real world.) Both go down over time/use. (Doh very, very slowly.. Maybe in 4 years you will lose 10% capacity or ~2-3Volts.) If you ride daily.

Edited August 21, 2022 by Funky

[mrelwood]

9 hours ago, Funky said:

How is it different? The max voltage decreases over time. Meaning the capacity goes "lower" by 0.001% or so. (You won't feel it in real world.) Both go down over time/use. (Doh very, very slowly.. Maybe in 4 years you will lose 10% capacity or ~2-3Volts.) If you ride daily.

That's not what happens. Like I said, my 14000km MSX still charged up to the same as new, as was expected since I took good care of balancing often.

The capacity that's lost is lost from the other end. The voltage drops faster while the battery is being used. The battery will still charge up to the charger voltage (it can't not, because the voltage difference of the charger and the batteries is what creates the charging current), but the charging process takes less time due to the lower capacity being put in the batteries.

In practice though, the balancing process sometimes gets longer, so the overall charging time probably remains roughly the same.

[0000]

To add some pictures to what @mrelwood said, it's not a bad thing to know a little bit about what's going on at the individual battery level as the batteries' internal chemistry degrades over the cycle life:

 

This graph shows all of the cell listed charged to the full 4.2V, then the initial voltage sag after a discharge current of 5C. From this graph you can also derive the amount of energy delivered (area under the curve) at that discharge current as each cell approaches the cut-off voltage of 2.5V.

 

Now take these same cells, now thoroughly abused, at 1000 cycles charged to their full capacity at 4.2V:

 

 

Notice the massive voltage sag immediately from the time that the discharge current is applied (which translates directly into a top-speed loss for one), this being evidence for a huge amount of internal battery chemistry degradation (though not surprising though with a pretty abusive 5C continuous discharge rate).

 

For example, from the graphs the P42A at a time of 100 seconds is at 3.7V in it's first cycle vs 3.5V in it's 1000th cycle. Like mrelwood said, all the cells still charge to the full 4.2V, but their performance will suffer as the batteries cycle through use. Looking at it another way and continuing with the example, the P42A's total energy delivered goes from 14.83Wh to 10.64Wh @ 0.2C for a 28% reduction in capacity after 1000 cycles. This cell and a couple others shown holds up relatively well, by comparison anyway, to this kind of abuse.

 

Source for graphs

[Circuitmage]

Nice charts. My takeaway is that the nicer cells only lose about 20% after 1000 recharges. Still usable.

 

[Begodecrashtestdummy]

On 8/21/2022 at 5:01 PM, Dosingpsychedelics said:

Definitely losing confidence in quality of euc’s .replaced dc converter at 2 months of buying it new ….now the capacitors blew And scorched the main board at around 4 months …sent ewheels an email just waiting to hear back from them but yes I’m becoming worried that eventually my wheel will burst into flames .

Already received my new board from ewheels and I just put it in the wheel .when I went to connect the xt90 connector I noticed no spark and the wheel would not power on ..so I checked the safety fuses on both batteries and sure enough thankfully when the capacitors blew it also blew the 30 amp safety fuses that go to both batteries.they are just regular 30 amp fuses .I would have to think if there was not those safety fuses the batteries could have caught fire .whew 

[mrelwood]

On 8/25/2022 at 7:24 PM, Circuitmage said:

Nice charts. My takeaway is that the nicer cells only lose about 20% after 1000 recharges. Still usable.

Another takeaway should be that 1000 full battery charge cycles on a 1800Wh wheel equals a total distance of about 80'000 - 100'000 km (50'000 - 62'500 miles). Double that on the Sherman Max, etc.

I haven't heard of anyone riding for more than 35'000km on any battery pack. That was on a Monster.

Insufficient balancing of the cells will always kill the pack far far sooner than any degradation.

[0000]

On 8/21/2022 at 9:01 PM, Dosingpsychedelics said:

Definitely losing confidence in quality of euc’s .replaced dc converter at 2 months of buying it new ….now the capacitors blew And scorched the main board at around 4 months …sent ewheels an email just waiting to hear back from them but yes I’m becoming worried that eventually my wheel will burst into flames .

So I was thinking about this, how those caps are oriented (presumably 90 degree orientation required for clearance) and very much not ideal long cap solder legs which clearly didn't hold up here. Here's an generic square-wave motor controller from an e-bike for capacitor comparison purposes.

I think in normal electrical design engineering, these legs are kept very short for reasons of efficiency and probably even reliability. Now I'm no electrical engineer, but you I would think there's easy room for improvement to add an adapter with a copper conduction path which would allow these cap legs to be soldered as short as possible in this orientation. Something like this:

Seems like some low-hanging fruit from my layman's perspective. Think it's worth forwarding to the eWheel suggestion box for a better chance to get through to the Begode team?