Battery problems

Does anyone *know* what cause(s) of recent/historical battery
fires (in EVs, particularly)?  I assume it is not related to
abuse or "usage hazards".  Or, charging/BMS.  But, rather,
originates in manufacturing (?)

Is this an issue with material (im)purities, mechanical defects,
assembly faults, etc.?

On 4/5/2022 6:46 AM, Don Y wrote:
> Does anyone *know* what cause(s) of recent/historical battery
> fires (in EVs, particularly)?  I assume it is not related to
> abuse or "usage hazards".  Or, charging/BMS.  But, rather,
> originates in manufacturing (?)
> 
> Is this an issue with material (im)purities, mechanical defects,
> assembly faults, etc.?

Said another way, is this a problem that has its cause at the factory
or after-the-sale?  (or, somewhere in-between)

On Tuesday, April 5, 2022 at 11:47:17 PM UTC+10, Don Y wrote:
> Does anyone *know* what cause(s) of recent/historical battery 
> fires (in EVs, particularly)? I assume it is not related to 
> abuse or "usage hazards". Or, charging/BMS. But, rather, 
> originates in manufacturing (?) 
> 
> Is this an issue with material (im)purities, mechanical defects, 
> assembly faults, etc.?

My guess is that it is going to be due to dendrite formation, leading to more rapid self-charge, which will lead to the core of the battery getting hotter than ambient, and even more rapid self-discharge.

At some point the process of self-discharge and self-heating will presumably run away, and the battery will get hot enough for the cells to burst and catch on fire.

I'd have imagined that batteries big enough for this to be a real risk would come with at least one temperature sensor at the core of the battery, and a microcontroller to read the sensor, process the data and warn the user, but I've not seen anything to suggest that people are actually doing this.

You'd need a temperature sensor if you want to use the voltage across the battery as much of an indicator of it's state of charge, so it ought to be a pretty obvious idea.

-- 
Bill Sloman, Sydney

--

On 05/04/2022 14:46, Don Y wrote:
> Does anyone *know* what cause(s) of recent/historical battery
> fires (in EVs, particularly)?  I assume it is not related to
> abuse or "usage hazards".  Or, charging/BMS.  But, rather,
> originates in manufacturing (?)

I'm not sure that there is one single cause.

Not necessarily a manufacturing problem so much as the intrinsically 
high energy density in such a battery when fully charged. It can fail 
various ways because of the high voltages, low internal resistance and 
peak currents involved.

> Is this an issue with material (im)purities, mechanical defects,
> assembly faults, etc.?

A fair proportion are provoked by high speed impacts. The others seem to 
include thermal runaway in cells that were not adequately protected by 
their thermal cutout for whatever reason and/or release valve failures.

I have yet to see an EV on fire myself. I see an ICE on fire by the 
roadside about every other year doing a fairly high mileage (lower now).

-- 
Regards,
Martin Brown

On Tuesday, April 5, 2022 at 7:21:26 AM UTC-7, Martin Brown wrote:
> On 05/04/2022 14:46, Don Y wrote: 
> > Does anyone *know* what cause(s) of recent/historical battery 
> > fires (in EVs, particularly)?  I assume it is not related to 
> > abuse or "usage hazards".  Or, charging/BMS.  But, rather, 
> > originates in manufacturing (?)
> I'm not sure that there is one single cause. 
> 
> Not necessarily a manufacturing problem so much as the intrinsically 
> high energy density in such a battery when fully charged. It can fail 
> various ways because of the high voltages, low internal resistance and 
> peak currents involved.
> > Is this an issue with material (im)purities, mechanical defects, 
> > assembly faults, etc.?

In case of the Bolt/LG, it was folded separators, manufacturing defects.

On Tue, 5 Apr 2022 15:21:18 +0100, Martin Brown
<'''newspam'''@nonad.co.uk> wrote:

>On 05/04/2022 14:46, Don Y wrote:
>> Does anyone *know* what cause(s) of recent/historical battery
>> fires (in EVs, particularly)?&#4294967295; I assume it is not related to
>> abuse or "usage hazards".&#4294967295; Or, charging/BMS.&#4294967295; But, rather,
>> originates in manufacturing (?)
>
>I'm not sure that there is one single cause.

Part is the huge number of ev vehicles on the road now.

>
>Not necessarily a manufacturing problem so much as the intrinsically 
>high energy density in such a battery when fully charged. It can fail 
>various ways because of the high voltages, low internal resistance and 
>peak currents involved.

Both reactants very close together, with large-scale chemical
exchanges every day.

>
>> Is this an issue with material (im)purities, mechanical defects,
>> assembly faults, etc.?
>
>A fair proportion are provoked by high speed impacts. The others seem to 
>include thermal runaway in cells that were not adequately protected by 
>their thermal cutout for whatever reason and/or release valve failures.
>
>I have yet to see an EV on fire myself. I see an ICE on fire by the 
>roadside about every other year doing a fairly high mileage (lower now).

I have never seen a car burning, or even a burned-out one on the side
of the road. In a junkyard maybe.



-- 

I yam what I yam - Popeye

On Tuesday, April 5, 2022 at 10:56:18 AM UTC-4, jla...@highlandsniptechnology.com wrote:
> On Tue, 5 Apr 2022 15:21:18 +0100, Martin Brown 
> <'''newspam'''@nonad.co.uk> wrote: 
> 
> >On 05/04/2022 14:46, Don Y wrote: 
> >> Does anyone *know* what cause(s) of recent/historical battery 
> >> fires (in EVs, particularly)?  I assume it is not related to 
> >> abuse or "usage hazards".  Or, charging/BMS.  But, rather, 
> >> originates in manufacturing (?) 
> > 
> >I'm not sure that there is one single cause.
> Part is the huge number of ev vehicles on the road now.
> > 
> >Not necessarily a manufacturing problem so much as the intrinsically 
> >high energy density in such a battery when fully charged. It can fail 
> >various ways because of the high voltages, low internal resistance and 
> >peak currents involved.
> Both reactants very close together, with large-scale chemical 
> exchanges every day.
> > 
> >> Is this an issue with material (im)purities, mechanical defects, 
> >> assembly faults, etc.? 
> > 
> >A fair proportion are provoked by high speed impacts. The others seem to 
> >include thermal runaway in cells that were not adequately protected by 
> >their thermal cutout for whatever reason and/or release valve failures. 
> > 
> >I have yet to see an EV on fire myself. I see an ICE on fire by the 
> >roadside about every other year doing a fairly high mileage (lower now).
> I have never seen a car burning, or even a burned-out one on the side 
> of the road. In a junkyard maybe. 

https://www.firehouse.com/photo-story/article/10550613/gasoline-tanker-bursts-into-flames-on-dc-beltway

https://www.nbcwashington.com/news/local/inner-loop-of-capital-beltway-closed-at-american-legion-bridge-due-to-tanker-crash/139440/

https://wtop.com/montgomery-county/2021/07/tanker-truck-overturned-leaking-liquid-asphalt-on-i-495-in-bethesda/

https://wtop.com/traffic/2021/06/truck-fire-blocks-all-thru-lanes-on-capital-beltways-inner-loop/

https://www.washingtonpost.com/archive/politics/1988/08/26/1-killed-4-injured-in-tanker-blast-fire-on-beltway/4c661c42-e034-4abd-b58f-9f5ccb1f3a42/

And here is one of the worst accidents I've every heard of...

https://www.washingtonpost.com/archive/politics/1992/10/20/fiery-fatal-crash-clogs-area-highways/9b54a77d-765c-45e7-bc44-253cd30812e9/

Gas tanker truck slams into a  bridge abutment, causing a fire so intense, they would not reopen the outer beltway loop until it could be inspected for structural damage from the steel being over temperature.  

I hope BEVs are adopted sooner, rather than later so we can get rid of the scourge called gasoline. 

-- 

Rick C.

- Get 1,000 miles of free Supercharging
- Tesla referral code - https://ts.la/richard11209 

On 4/5/2022 7:21 AM, Martin Brown wrote:
> On 05/04/2022 14:46, Don Y wrote:
>> Does anyone *know* what cause(s) of recent/historical battery
>> fires (in EVs, particularly)?  I assume it is not related to
>> abuse or "usage hazards".  Or, charging/BMS.  But, rather,
>> originates in manufacturing (?)
> 
> I'm not sure that there is one single cause.

Well, that would be "information", too!

> Not necessarily a manufacturing problem so much as the intrinsically high 
> energy density in such a battery when fully charged. It can fail various ways 
> because of the high voltages, low internal resistance and peak currents involved.

What I'm getting at is where efforts could/should be directed to address
this.

E.g., if it was due to impurities in the materials used, then better
"refining".  If due to high charge (regen braking)/discharge rates,
better battery/load management.  If due to mechanical damage ("collisions"),
better physical protections.

I'm also wondering how the issue might play into recycling efforts.
As the raw materials become more difficult to acquire, I suspect
that will see more attention.

We "know" how lead-acid batteries fail.  And, can largely recycle their
materials without worsening that failure rate.  Will the same hold
for these EV batteries?  Or, will they effectively become "scrap"
(again, depending on how the failures manifest)

>> Is this an issue with material (im)purities, mechanical defects,
>> assembly faults, etc.?
> 
> A fair proportion are provoked by high speed impacts. The others seem to 
> include thermal runaway in cells that were not adequately protected by their 
> thermal cutout for whatever reason and/or release valve failures.

That would seem to be addressable by design changes...

> I have yet to see an EV on fire myself. I see an ICE on fire by the roadside 
> about every other year doing a fairly high mileage (lower now).

I suspect that is related to the distribution of ICE vs EV products out there.
I can only claim to have seen (first hand) a single engine fire in a lifetime
of driving.  Though I have seen burnt out hulks (often "getting a ride" to
<someplace>).

[P.S. Did you finish your research/paper?]

On 4/5/2022 7:47 AM, Ed Lee wrote:
>>> Is this an issue with material (im)purities, mechanical defects,
>>> assembly faults, etc.?
> 
> In case of the Bolt/LG, it was folded separators, manufacturing defects.

That *sounds* like it could be easily corrected, going forward
(unless there is something that makes that particular aspect of
manufacture "troublesome")

On Tuesday, April 5, 2022 at 4:37:48 PM UTC-7, Don Y wrote:
> On 4/5/2022 7:47 AM, Ed Lee wrote: 
> >>> Is this an issue with material (im)purities, mechanical defects, 
> >>> assembly faults, etc.? 
> > 
> > In case of the Bolt/LG, it was folded separators, manufacturing defects.
> That *sounds* like it could be easily corrected, going forward 
> (unless there is something that makes that particular aspect of 
> manufacture "troublesome")

It's mostly QA/QC problem, but the troubling part is that it was not discovered until 100,000 Bolt batteries were already made.