Begode 900Wh Battery Recall Options

[RockyTop]

How is the S18 so different? ( NOT LG M50LT? And a fuse? Limiting software? ) It only has 3 parallels and does  not seem to have these problems. 
 

The 21700 has always concerned me because it is bigger in diameter. Thicker means that heat becomes more of a problem. Keep in mind that the batteries use the same materials inside they are just packaged in deeper. The middle layer is further from heat dissipation. The S18 single stacks in an aluminum casing that acts as an open air heat sync. Do we have an overheating issue adding to the problem? 
 

The RS19 double stacks in several layers of warm plastic. 
 

Also the aluminum case on the S18 might just keep a fire cell contained?  

[Planemo]

I find this all highly scary. So glad I don't own any 900wh packs thats for sure. But having read through this thread, I still don't see any answers as to WHY this is happening with GW.

So it seems that many other wheels also use the LG50LT cells and haven't had nearly the ratio of fire issues. So that seems to rule out the cell manufacturer/type.

The 900Wh packs likely don't have any less protections on their BMS' compared to the older (far less fire prone) MSX 18650 BMS', so I don't think it's the BMS which is the issue either.

Some fires have happened with wheels that are either new or very new, so we can rule out rider misuse/poor charging practises. This same point would also suggest ruling out the question over whether the cells themselves have a suitable current output when configured in the 900Wh packs.

I hear someone mention the poor quality interconnects on the 900Wh packs. Are these lower spec than the older 800Wh 18650 packs? If not, we can rule that out as well, especially given that even if they are lower quality on the 900Wh packs, fires have happened on new wheels so again it seems unlikely to be an interconnect problem.

To me, it seems we are rapidly running out of potential things to point our fingers at. I am kinda left at:

1. Use of 2nd grade/untested/unmatched/second hand/counterfeit/poor QC'd cells.

2. A reduction in the general quality of pack construction compared to the older 800Wh packs. But you gotta have some serious reduction to enable brand new/nearly new packs to fail. So I'm not convinced on this.

Unless anyone else can think of anything, it mainly leaves point 1. as the culprit from where I am standing?

[Menace]

So how is this recall going to work?

[RockyTop]

3 minutes ago, Planemo said:

So it seems that many other wheels also use the LG50LT cells

Real question: What other wheel uses these batteries in a double stack configuration inside a plastic case that has had real world testing? 

[Paul A]

Think Adam Wrong Way in his video was surmising that some of the reason(s) why Gotways are burning are:

Extreme demands placed on the wheel by riders because Gotways are supposed to be high performance wheels.

Gotway fuse is actually non effectual.

[supercurio]

2 hours ago, Jason McNeil said:

What's really worrying about a couple of the cases that have been reported, is that there's no prior warnings/symptoms before it goes critical, leading to a chain reaction in the pack.

Besides the lack of safety mechanisms in either the board, BMS, or these LG M50LT cells, there seems two main factors at play: the accelerated aging/dendritic formation by operating outside the operating spec & pack manufacturing issues. Those in the latter group would explain instances of brand new Wheels catching on fire, as well as the battery container fire from earlier in the year.         

With the LiTech battery project, we had to work on premise that Begode were not going to accommodate the request to add CANBUS, or other BMS communication channel to the controller, the packs needed to be self-contained for providing independent alerting for elevated operating temperatures, cell failure, or other malfunction. 

Compared to the LG M50LT, the Samsung 50E offers a 25% performance margin (~7.5A vs 10A sustained), running cooler, without any nominal capacity loss; even on cost grounds, the two cell types are pretty comparable.

Manufacturers like King Song  & Inmotion are probably able to use the LG M50LT, because they have better current rate limiting in their firmware. Pushing beyond the limits of a particular cell's spec might be fine in a lab setting, or single use operation, but in a machine where the expected life-span is several years, microscopic cell damage is insidious & accumulative; it might be fine weeks, months, possibly even years later, the trouble is that no-one knows just when it will go critical.      

I asked our LiTech contact, Henry, to provide a video demonstrating the packs thermal performance under conditions that are well outside the normal operating envelope 60A sustained....    

1. Keep discharging with 60A current on 24S4P, battery can run about 10 minutes, then fuse blew and high temp. rised and triggered the buzzer,
   So the result is current from 30A-60A is safe on 24S4P pack, but more than 60A the BMS will be easily trigger the over temp protections and fuse could be blew away if more than 10 minutes drawing.
2. Current more than 102A, in a few seconds the fuses blew, that measn any current more than 100A in a few seconds our fuses could be below

 

 

Really appreciate you are sharing these details, being transparent although it could worry customers and upset Begode.

I think that we are past the breaking point, and strict requirements must be imposed to OEMs who are not willing to make it happen by themselves.
Our whole community will suffer from the consequence if more wheels are sold without robust battery safety mechanism in place and thoroughly tested.
Regular people will fear them, they'll be banned from any public transportation, restaurants etc.. It's not unrealistic it might just end EUCs altogether as a trend, as brief as strange.

Just like it was not acceptable to have a Samsung Galaxy Note phone catch fire, it is not acceptable to have EUCs burst in flames.
The smartphone industry took that seriously, and it's essentially a thing of the past. From your report Begode is clearly not, pushing back on industry standard features.

@Jason McNeilI'll send you a MP regarding potential development of an app / wireless protocol to connect to smart BMS (retrofit)
Packs having their own alarms are already a great improvements. It's possible to go further.

[YourAubsome]

@Jason McNeil really important question:

ewheels appears to be doing a recall on the wheels that they sold to their customers. Unfortunately, most of the fire hazard gotway/begode wheels in the world were not sold by ewheels. Do you have any idea as to what other vendors will be doing with the fire hazard wheels? I seriously doubt gotway would actually do a recall themselves. I don't know if gotway or other vendors will even admit that there is a problem. 

Unfortunately I bought my RS19 from RevRides because there was a super long wait to get one from ewheels... and that wait was likely because you were trying to fix the fire hazard problem 🤦‍♂️.

I posted this in the ElectricUnicycle.org facebook group on July 23rd 2021 and almost everyone ignored it:

 

Quote

 

GM already recalled 68,000 Bolts because 5 Bolts caught on fire over a 2 year period. Now they are recalling even more of the cars because they don’t believe the issue is fully solved. I can’t find the exact numbers but it looks like GM sold about 140,000 Bolts in that 2 year period, and 5 of them caught on fire. https://www.engadget.com/gm-recalls-bolt-evs-once-again...
 

There have been a total of 13 Gotway wheels that caught on fire in the last 5 years or so ( https://forum.electricunicycle.org/.../21506-smoke-fire... ). I don’t know how many wheels Gotway has sold but I can’t imagine its beyond 100,000. I’m pretty sure Gotway has issued zero recalls over their wheels catching on fire. This lack of safety is a major problem

 

 

[RagingGrandpa]

1 hour ago, Chriull said:

I don't see any sane way to protect against this with an EUC World alarm, because

- begode wheels report no battery current but motor current which is something completely different.

Seba added Gotway battery current estimation in EUC World, which is a function of speed and motor current. So it's not a direct measurement; but it's useful. Example log here: estimates 18A @ 93V for 30mph riding.

 

43 minutes ago, RockyTop said:

the aluminum case on the S18 might just keep a fire cell contained?  

Not a chance

 

32 minutes ago, RockyTop said:

What other wheel uses [M50T] batteries in a double stack configuration inside a plastic case that has had real world testing? 

Gotway is the only brand in production so far.

(Perhaps there are other examples in esk8 / escooters / ebikes? Not sure myself...)

[supercurio]

@Jason McNeil I couldn't send you a private message in forums so I sent to sales@ewheels.com instead.
Hopefully they'll forward.

In short:
It's a proposal with a plan to enable smart BMS features suitable for EUCs on your custom packs, and bypass Begode's obstruction.
I mean it's not just a plan. As developer, I'm very confident we can make it happen.

[Planemo]

48 minutes ago, RockyTop said:

Real question: What other wheel uses these batteries in a double stack configuration inside a plastic case that has had real world testing? 

I'm not sure that the stack configuration or indeed the packaging is a problem when new/nearly new wheels have caught fire. Therefore I think we need to look outside the area of user abuse/hard riding.

41 minutes ago, supercurio said:

 although it could worry customers and upset Begode.

I would have thought Begode were a little upset a fair while back, when ewheels announced they were going to use their own packs for Begode wheels. That kinda insinuates something lol.

41 minutes ago, supercurio said:

Packs having their own alarms are already a great improvements. It's possible to go further.

It's an improvement, but I am not convinced that any alarms would prevent the immediate and catastrophic situations we have seen some of these wheels ignite in. I am not even convinced it's a cell imbalance issue tbh, given as I have already said (people will get bored of me saying this) that it's happened with brand new/nearly new wheels. These cells are just seeming to spontaneously combust, without warning, at any time. Thats gotta be a problem with the cells themselves surely?

I appreciate that an overheat alarm may well give the owner a chance to at least get the wheel outside, but once a cell goes thermonuclear theres very little time... 

[supercurio]

2 minutes ago, Planemo said:

It's an improvement, but I am not convinced that any alarms would prevent the immediate and catastrophic situations we have seen some of these wheels ignite in. I am not even convinced it's a cell imbalance issue tbh, given as I have already said (people will get bored of me saying this) that it's happened with brand new/nearly new wheels. These cells are just seeming to spontaneously combust, without warning, at any time. Thats gotta be a problem with the cells themselves surely?

I appreciate that an overheat alarm may well give the owner a chance to at least get the wheel outside, but once a cell goes thermonuclear theres very little time... 

Agree. I don't think that one safety measure (allowing to monitor battery health, force the rider to stop riding or stop charging when any fault is identified) is sufficient.

I believe that all of the QC and safety mechanisms are necessary at the same time.
From picking only the good cells during manufacturing, to offering a comprehensive reports of battery health and ageing in an app to the end user.

[Planemo]

6 minutes ago, supercurio said:

From picking only the good cells during manufacturing, to offering a comprehensive reports of battery health and ageing in an app to the end user.

Yeah we all definitely need per string monitoring like the Z10 did. But I still don't think this is the real answer. Theres a fundamental problem with these 900Wh packs somewhere that I don't think any amount of monitoring/alarms would solve.

[RockyTop]

Well? The quickest way to catch one of these batteries on fire is to short it. The Gotway wheels seem to amp spike harder and sharper than any other wheel. 

[Paul A]

Alarms and warnings are reliant on a person being present, aware of the alarm, know what the alarm signifies, what to do, react quickly enough, have quick access to take the wheel outside to a place where it can burn safely.......so many things need to be right for an outcome without serious injury/death.

 

The Portland, Oregon, Gotway fire was self ignition at night when the occupants were asleep. 

Think a smoke alarm alerted them.

The wheel had been dormant for a few days prior.

 

The Grenfell Tower fire in London was caused by a malfunctioning fridge-freezer on the fourth floor.

It spread rapidly up the building's exterior, bringing fire and smoke to all the residential floors.

This was due to the building's cladding, the external insulation and the air gap between which enabled the stack effect.

Seventy one people died.

[Bizra6ot]

What about the samsung 48x begode packs like in Ex.n, is it better or worse than the lg?

https://ecodrift.ru/wp-content/uploads/2021/07/Monokoleso-Begode-EX-N-10.jpg

 

[mike_bike_kite]

Roughly what percentage of wheels with 900wh batteries are having these issues? (1 in 10? 100? 1000? 10000?)

[Planemo]

53 minutes ago, RockyTop said:

Well? The quickest way to catch one of these batteries on fire is to short it. The Gotway wheels seem to amp spike harder and sharper than any other wheel. 

Agreed, but we're not answering why they are shorting....even when not being ridden....or even when they are new... (oops I said it again)

[Planemo]

34 minutes ago, Bizra6ot said:

What about the samsung 48x begode packs like in Ex.n, is it better or worse than the lg?

Good point. I don't know. But it would sure help if it was found that there were less/no EXN fires. At least it would suggest that it's an LG problem rather than a '21700' problem.

It may not even be an LG problem if the cells in question are counterfeit...I'd love to run some charge/discharge tests on an 'LG' cell from a wheel that had caught fire.

1 minute ago, mike_bike_kite said:

Roughly what percentage of wheels with 900wh batteries are having these issues? (1 in 10? 100? 1000? 10000?)

I think we would struggle with finding this data Mike. Suffice to say, the fact that ewheels have an issue with the packs and they are obviously a big retailer of all wheels suggests that whatever the percentage, it's enough to be a concern.

[Denny Paul]

21 minutes ago, Planemo said:

Agreed, but we're not answering why they are shorting....even when not being ridden....or even when they are new... (oops I said it again)

Isn’t the running theory that the motors are drawing some number of amps that is beyond the spec of the batteries? And over time can cause something called dendrite formation, which makes the batteries unsafe to use.

As for new batteries, I’d think that’s just a manufacturing defect, qc problem. two nodes too close to each other than are able to arc and short. 

Edited November 9, 2021 by Denny Paul

[Tawpie]

9 minutes ago, Denny Paul said:

Isn’t the running theory that the motors are drawing some number of amps that is beyond the spec of the batteries? And over time can cause something called dendrite formation, which makes the batteries unsafe to use.

That's exactly how I'm reading it... repeated over stressing of the individual cells is "bad" and ultimately can lead to catastrophic failure. The solutions proposed are "ride like Marty" (don't over stress your battery cells) and "fix the firmware so you can't over stress the cells, and fix the hardware if necessary".

The downside is either way, you won't have Gotway performance unless you have Sherman batteries (I wonder if battery protection is part of why the Sherman is 'slow off the line'?)

Edited November 9, 2021 by Tawpie

[Planemo]

6 minutes ago, Denny Paul said:

Isn’t the running theory that the motors are drawing some number of amps that is beyond the spec of the batteries? And over time can cause something called dendrite formation, which makes the batteries unsafe to use.

As for new batteries, I’d think that’s just a manufacturing defect, qc problem. two nodes too close to each other than are able to arc and short. 

As I say, I am not convinced that all the battery fires on used wheels can be attributed to the riders drawing excessive amps. Nor that all the new/nearly new wheel fires can be attributed to manufacturing defects. Just my opinion though.

[Denny Paul]

Food for thought, something like this is why I personally think powerpads aren't a great idea. It's just an afterthought way to get more juice out of the wheel, power that wasn't intended to come out when say the manufacterers were making the wheel. The amount that you're allowed to crunch down on the wheel with powerpads probably is akin to carrying around a person thats 400lbs, or whatever is beyond the intended max weight of the rider.

Even still fault still is with the manufacturers on this. There's a several things they could have done instead that would have been way better. They should know that a small percent of people will use what they buy to the max possible, and should have added a hard upper limit somewhere.

[Denny Paul]

10 minutes ago, Planemo said:

As I say, I am not convinced that all the battery fires on used wheels can be attributed to the riders drawing excessive amps. Nor that all the new/nearly new wheel fires can be attributed to manufacturing defects. Just my opinion though.

from what ive seen it seems that wheel fires are often due to failing to charge to full on a regular basis. Or water damaged wheels. Or wheels in crashes with dented/damaged battery packs. Or even a delayed manufacturing defect. And in light of this news, now the possibility of amp draw thats beyond the batteries abilities can supposedly start the chain reaction leading to a fire. 

no one said 'all'

[shellac]

I may be talking out of my ass here, but wouldn’t moving to LiFePo4 21700 batteries greatly reduce the risk of fire as well? Are there practical reasons why this isn’t an option?

Thanks to @Jason McNeil for working on this recall. Glad to hear eWheels is recovering. 

[Chriull]

24 minutes ago, shellac said:

but wouldn’t moving to LiFePo4 21700 batteries greatly reduce the risk of fire as well? Are there practical reasons why this isn’t an option?

The energy density.

And the li ion work out for all wheels but begode...

Edited November 9, 2021 by Chriull