Re: [EVDL] Large Format Cells vs. Small Format Cells for EVs

[Michael Ross via EV]

y of those tests, and their
practicality.  We end up falling prey to our confirmation biases and
shrugging off the uncertainty of it all because the whole boneheaded
tradition is confusing at best.

Learn what the best people have learned, and stop thinking the old ways.

On Fri, Sep 14, 2018 at 5:59 AM George Tyler via EV 
wrote:

> From my experience, we had an in-house test company that ran independently,
> we wanted to know the truth, results are not released to the public but
> used
> to improve reliability. The name of the company is at stake. When I see
> something like a cell phone company that has battery fires I know it's
> either a mickey mouse company, or someone did not do their job properly!
> There is nothing to be gained by "fudging" results
> component failure should follow a "bath tub" shape, on a graph of
> failure rate on the vertical axis and time on the horizontal. The shape can
> tell a lot about product quality, you are testing many samples, and they
> should lie on the same curve. Bad production methods or bad component
> quality can be indicated by a spread in different ways. We also tested
> components like the SCR's used in the same manner, we ran 70A SCR's at over
> 1000 amps, tested many samples for months like that, also tested spade
> terminals used in the products.
>
>
> -Original Message-
> From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of Lee Hart via EV
> Sent: 13 September, 2018 4:46 PM
> To: Electric Vehicle Discussion List
> Cc: Lee Hart
> Subject: Re: [EVDL] Large Format Cells vs. Small Format Cells for EVs
>
> Michael Ross via EV wrote:
> > Yeah, I wouldn't say prove either. But testing can be far better than the
> > old tried, and not very good cycling tests.
>
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Re: [EVDL] Large Format Cells vs. Small Format Cells for EVs

[Lee Hart via EV]

George Tyler via EV wrote:

From my experience, we had an in-house test company that ran independently,

we wanted to know the truth, results are not released to the public but used
to improve reliability. The name of the company is at stake. When I see
something like a cell phone company that has battery fires I know it's
either a mickey mouse company, or someone did not do their job properly!
There is nothing to be gained by "fudging" results


Amen to that, George! That is exactly my experience. I worked designing 
furnace controls and large home appliance controls. These are consumer 
products (have to be cheap), but are also expected to last a long time 
(decades) and also MUST be safe! That meant the product testing cost 
more than the parts.


Cars have to be designed the same way; otherwise they can KILL somone!

--
Imagination is your preview of life's coming attractions.
(Albert Einstein)
--
Lee Hart, 814 8th Ave N, Sartell MN 56377, www.sunrise-ev.com
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Re: [EVDL] Large Format Cells vs. Small Format Cells for EVs

[George Tyler via EV]

>From my experience, we had an in-house test company that ran independently,
we wanted to know the truth, results are not released to the public but used
to improve reliability. The name of the company is at stake. When I see
something like a cell phone company that has battery fires I know it's
either a mickey mouse company, or someone did not do their job properly!
There is nothing to be gained by "fudging" results
component failure should follow a "bath tub" shape, on a graph of
failure rate on the vertical axis and time on the horizontal. The shape can
tell a lot about product quality, you are testing many samples, and they
should lie on the same curve. Bad production methods or bad component
quality can be indicated by a spread in different ways. We also tested
components like the SCR's used in the same manner, we ran 70A SCR's at over
1000 amps, tested many samples for months like that, also tested spade
terminals used in the products.


-Original Message-
From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of Lee Hart via EV
Sent: 13 September, 2018 4:46 PM
To: Electric Vehicle Discussion List
Cc: Lee Hart
Subject: Re: [EVDL] Large Format Cells vs. Small Format Cells for EVs

Michael Ross via EV wrote:
> Yeah, I wouldn't say prove either. But testing can be far better than the
> old tried, and not very good cycling tests.

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Re: [EVDL] Large Format Cells vs. Small Format Cells for EVs

[Jukka Järvinen via EV]

Yes. Still few people understand about li-ion. The main thing to understand
is there is so many different ways to make them it is quite impossible to
know enough to make any general assumptions. There’s maybe less than dozen
people in the world who can say anything in general. I can only say I know
those cells I am making and which I have been litterallyt living with
almost two decades. It is not about knowing all but to know what one
specific cell type can do. And when certain treshold of knowledge is met
most things around it can be optimized to get the job done (what ever it
is). -Jukka


to 13.9.2018 klo 10.24 Michael Ross via EV  kirjoitti:

> Hi Lee,
>
> You were kind enough to talk with me bit a while back, and you were right
> on. We wanted to build a testing lab using the Novonix equipment, but it
> was clear the general population of Li ion users who might benefit from
> actually knowing: neighborhood vehicles, scooters, eBikes and so on,
> prefered to be ignorant of the actual quality and durability of the cells
> they were buying. Likewise they had little understandind how their
> controllers and charging systems worked, and how to do some QC on that
> incoming material.
>
> If you are a Medtronix, or a Tesla, where you have a big money need to get
> it right then this testing looks like how you stay ahead of competition.
> They can afford the $1M ticket to have inhouse testing, or make deals just
> as those two mentioned did with Dalhousie.
>
> And so 4 years down the line, still, few people understand how the cells
> work, how they are manufactured well, what real quality looks like, what
> the real life in an application might be.
>
> Anyway, funding a lab and having it actually pay salaries looked near
> impossible.
>
> Mike
>
>
> On Thu, Sep 13, 2018 at 12:41 AM Lee Hart via EV 
> wrote:
>
> > Michael Ross via EV wrote:
> > > Yeah, I wouldn't say prove either. But testing can be far better than
> the
> > > old tried, and not very good cycling tests.
> >
> > It all depends on who is doing the testing, and why.
> >
> > If it's being done by marketing to promote sales, they're likely to pick
> > a test procedure that gives the best results possible. Often, they won't
> > specify the test procedure used, or leave out crucial information.
> >
> > If it's done by a customer, to evaluate how long it's likely to last in
> > their product, they are more likely to strive for meaningful test
> results.
> >
> > If it's done by an independent researcher, look at who's paying for the
> > testing.
> > --
> > Imagination is your preview of life's coming attractions.
> > (Albert Einstein)
> > --
> > Lee Hart, 814 8th Ave N, Sartell MN 56377, www.sunrise-ev.com
> > ___
> > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
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> > http://groups.yahoo.com/group/NEDRA)
> >
> >
>
> --
> Michael E. Ross
> (919) 585-6737 Land
> (919) 901-2805 Cell and Text
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Re: [EVDL] Large Format Cells vs. Small Format Cells for EVs

[Michael Ross via EV]

Hi Lee,

You were kind enough to talk with me bit a while back, and you were right
on. We wanted to build a testing lab using the Novonix equipment, but it
was clear the general population of Li ion users who might benefit from
actually knowing: neighborhood vehicles, scooters, eBikes and so on,
prefered to be ignorant of the actual quality and durability of the cells
they were buying. Likewise they had little understandind how their
controllers and charging systems worked, and how to do some QC on that
incoming material.

If you are a Medtronix, or a Tesla, where you have a big money need to get
it right then this testing looks like how you stay ahead of competition.
They can afford the $1M ticket to have inhouse testing, or make deals just
as those two mentioned did with Dalhousie.

And so 4 years down the line, still, few people understand how the cells
work, how they are manufactured well, what real quality looks like, what
the real life in an application might be.

Anyway, funding a lab and having it actually pay salaries looked near
impossible.

Mike


On Thu, Sep 13, 2018 at 12:41 AM Lee Hart via EV  wrote:

> Michael Ross via EV wrote:
> > Yeah, I wouldn't say prove either. But testing can be far better than the
> > old tried, and not very good cycling tests.
>
> It all depends on who is doing the testing, and why.
>
> If it's being done by marketing to promote sales, they're likely to pick
> a test procedure that gives the best results possible. Often, they won't
> specify the test procedure used, or leave out crucial information.
>
> If it's done by a customer, to evaluate how long it's likely to last in
> their product, they are more likely to strive for meaningful test results.
>
> If it's done by an independent researcher, look at who's paying for the
> testing.
> --
> Imagination is your preview of life's coming attractions.
> (Albert Einstein)
> --
> Lee Hart, 814 8th Ave N, Sartell MN 56377, www.sunrise-ev.com
> ___
> UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
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> http://groups.yahoo.com/group/NEDRA)
>
>

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Re: [EVDL] Large Format Cells vs. Small Format Cells for EVs

[Lee Hart via EV]

Michael Ross via EV wrote:

Yeah, I wouldn't say prove either. But testing can be far better than the
old tried, and not very good cycling tests.


It all depends on who is doing the testing, and why.

If it's being done by marketing to promote sales, they're likely to pick 
a test procedure that gives the best results possible. Often, they won't 
specify the test procedure used, or leave out crucial information.


If it's done by a customer, to evaluate how long it's likely to last in 
their product, they are more likely to strive for meaningful test results.


If it's done by an independent researcher, look at who's paying for the 
testing.

--
Imagination is your preview of life's coming attractions.
(Albert Einstein)
--
Lee Hart, 814 8th Ave N, Sartell MN 56377, www.sunrise-ev.com
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Re: [EVDL] Large Format Cells vs. Small Format Cells for EVs

[Michael Ross via EV]

With all due respect, this is not an effective way to demonstrate that a Li
ion battery will last any particular amount of time.

The test method currently the most likely to generate useful results
examines coulombic efficiency to evaluate how small changes to electrollyte
chemistry, electrode construction and content, etc., effect the degradation
of Li ion cells.

*Lithium Battery Research, Jeff Dahn, Dalhousie/Tesla Motors*
I haven't listened carefully to this one yet.
https://www.youtube.com/watch?v=5WpQh4kZ_MU

This video exposes the best testing of Li ion cells and talks about why it
is better in detail.
This is very much worth studying closely to understand testing of Li ion
cells.
*Why do Li-ion Batteries die ? and how to improve the situation?*
https://www.youtube.com/watch?v=pxP0Cu00sZs

A little TEDx bio and promo for the Dahn Lab at Dalhousie U in Nova Scotia
https://www.youtube.com/watch?v=MpHW35gtn54=620s

*Search for vids realted to the Dahn Lab*
https://www.youtube.com/results?search_query=jeff+dahn+lithium+battery

If someone wants to talk sense about Li ion testing this will get you
started.  Without this?  Not much sense.

On Tue, Sep 11, 2018 at 8:50 PM George Tyler via EV 
wrote:

> It is not a test done on 1 product, it is all work out statistically, it
> will be something like, "if you test 100 batteries with acceleration
> factor X for 3 months, then you will be 97% confident it that it will
> last 10 years in the car." At Gallaghers (electric fence manufacturers)
> we had 1 guy to do this calculation and control the test, results were
> amazing, reduced failure rate right down.
>
>
> On 12-Sep-18 12:08 PM, EVDL Administrator via EV wrote:
> > On 11 Sep 2018 at 15:48, Jan Steinman via EV wrote:
> >
> > "And then the only thing you've proven is that THAT battery lasted 10
> years."
> >
> >
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> >
> >
>
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Re: [EVDL] Large Format Cells vs. Small Format Cells for EVs

[Michael Ross via EV]

Yeah, I wouldn't say prove either. But testing can be far better than the
old tried, and not very good cycling tests.

The program a the Dahn Lab at Dalhousie University (
https://www.dal.ca/diff/dahn/publications.html  ) developed super sensitive
methods for examining Li ion batteries.  They can detect deterioration  of
the cells in a relatively short amount of time and correlate that to life
cycle.  Did they do that with LiFePO?  I am not sure about that.  His grad
students have gone on to work for Tesla (Aaron Smith as engineer in charge
of cell life), and to develop testing equipment for sale to battery
manufacturers (Chris Burns, Novonix Battery Testing Services Inc.).

See: 422. A.J. Smith, J.C. Burns, S. Trussler and J.R. Dahn, Precision
Measurements of the Coulombic Efficiency of Lithium-ion Batteries and of
Electrode Materials for Lithium-ion Batteries, J. Electrochem. Soc. 157,
A196-A202 (2010).

Definitely better than the anecdotal evidence and poorly conceived cycle
testing that was and probably still is prevalent at LiFePO manufacturers.
(Didn't this thread drift to LiFePO and a claim of 1 cycle life?)  I
tried to get a sense from Chinese large cell manufactures and pack
constructors if they understood what their testing did, and to see if they
were aware of what was being developed.  They were pretty mystified by my
questions; could be I never had conversation with the right people, but I
think they were just happy to have sales without worrying to much about
testing representing the real world.

LiFePO cells can be long lasting, but they are easily damaged if
temperatures in the 90F range are experienced while the cells are fully
charged. My own anecdotal evidence bore this out. I ruined packs charging
them in a hot location with far fewer than 1 cycles.

On Tue, Sep 11, 2018 at 7:04 PM Jan Steinman via EV 
wrote:

> > From: "George Tyler" 
> >
> > it is all proven science, you can prove a lifetime of 10 years
>
> "Prove" is a pretty strong word, a word that scientists rarely use.
> "Proofs" are for mathematicians and lawyers; scientists generally speak of
> "evidence."
>
> If you'd say, "There's a pretty high confidence level that these batteries
> will last ten years," I wouldn't argue. But the only way you "prove" that a
> battery will last ten years is to use it for ten years.
>
> Jan
>
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Re: [EVDL] Large Format Cells vs. Small Format Cells for EVs

[George Tyler via EV]

It is not a test done on 1 product, it is all work out statistically, it 
will be something like, "if you test 100 batteries with acceleration 
factor X for 3 months, then you will be 97% confident it that it will 
last 10 years in the car." At Gallaghers (electric fence manufacturers) 
we had 1 guy to do this calculation and control the test, results were 
amazing, reduced failure rate right down.



On 12-Sep-18 12:08 PM, EVDL Administrator via EV wrote:

On 11 Sep 2018 at 15:48, Jan Steinman via EV wrote:

"And then the only thing you've proven is that THAT battery lasted 10 years."


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Re: [EVDL] Large Format Cells vs. Small Format Cells for EVs

[George Tyler via EV]

It is the meaning of "lifetime" i think, that is in question, of course 
not every battery will last 10 years, i should have said "expected 
lifetime", i guess.




On 12-Sep-18 10:48 AM, Jan Steinman via EV wrote:

From: "George Tyler" 

it is all proven science, you can prove a lifetime of 10 years

"Prove" is a pretty strong word, a word that scientists rarely use. "Proofs" are for 
mathematicians and lawyers; scientists generally speak of "evidence."

If you'd say, "There's a pretty high confidence level that these batteries will last ten 
years," I wouldn't argue. But the only way you "prove" that a battery will last ten 
years is to use it for ten years.

Jan

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Re: [EVDL] Large Format Cells vs. Small Format Cells for EVs

[EVDL Administrator via EV]

On 11 Sep 2018 at 15:48, Jan Steinman via EV wrote:

> If you'd say, "There's a pretty high confidence level that these batteries
> will last ten years," I wouldn't argue. But the only way you "prove" that a
> battery will last ten years is to use it for ten years.

And then the only thing you've proven is that THAT battery lasted 10 years.

David Roden - Akron, Ohio, USA
EVDL Administrator

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Re: [EVDL] Large Format Cells vs. Small Format Cells for EVs

[Jan Steinman via EV]

> From: "George Tyler" 
> 
> it is all proven science, you can prove a lifetime of 10 years

"Prove" is a pretty strong word, a word that scientists rarely use. "Proofs" 
are for mathematicians and lawyers; scientists generally speak of "evidence."

If you'd say, "There's a pretty high confidence level that these batteries will 
last ten years," I wouldn't argue. But the only way you "prove" that a battery 
will last ten years is to use it for ten years.

Jan

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Re: [EVDL] Large Format Cells vs. Small Format Cells for EVs

[George Tyler via EV]

Also worked on SONAR, really interesting stuff. Had a 1,8m high bay full of
processors, detecting ship's propeller noise. Each one had the sound of a
known ship's prop stored in ROM and did a correlation to find which ship it
was. Also did some work on the fire control for the torpedo's. those had a
speed of 24 knots, while the Russian nuclear sub had been clocked at 50, so
the subs could do circles around the torpedos. 
The other thing about Batteries. And big manufacturer now does HALT
testing highly accelerated life testing) to prove the life of components, it
is all proven science, you can prove a lifetime of 10 years in a test taking
3 months. 


-Original Message-
From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of Jan Steinman via EV
Sent: 10 September, 2018 4:47 PM
To: ev@lists.evdl.org
Cc: Jan Steinman
Subject: Re: [EVDL] Large Format Cells vs. Small Format Cells for EVs

> From: George Tyler 
> 
> I used to design electronics for 
> military, (submarines) you can make MTBF say whatever you want!

Yea, so true. The Navy got so frustrated that they abandoned static analysis
for real-time testing.

I worked on linear beam forming for subs. We used card-edge scan testing
during retrace time, when the virtual beam was essentially scanning back
through the hull. Each bus interface unit had a Motorola 68000 on it, just
to control the testing, 60 times a second.

Jan

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Re: [EVDL] Large Format Cells vs. Small Format Cells for EVs

[Jukka Järvinen via EV]

Unknown future problems? What are you referring to? This is well documented
failure mode. That is the very reason of having the fuse there. :) It is
not due manufacturing defect.

Empirical evidence is empirical. One has to see it with own eyes. It does
not mean it is in public domain. Most important to make it scientific and
useful is to have all well documented and verified with proven evidence.
This is what Tesla is doing by not telling openly what is their empirical
evidence on the drive battery failure modes. It's their way to keep ahead
of the competition. Just like what I have been doing for the past ~20 years
in this field of business. I use the knowledge to improve my products and
innovations to create more innovations and make sure we survive the climate
change (while it all started with deep love to EV and technology 25 years
ago).

15 years of operational lifetime has been now proven with LiFePO4-Graphite.
Adding the new innovations on that base track record is basis on my claim
we are going to witness even better results. This is why I *see* this as a
*possible* outcome. 500Wh/kg can be achieved in printed thin film cells
which have been plagued with certain issues regarding certain things. Vague
enough? :D

-Jukka


su 9. syysk. 2018 klo 21.19 Jan Steinman via EV (ev@lists.evdl.org)
kirjoitti:

> > From: Jukka J?rvinen 
> >
> > The main question is when will the problems be there? After 200.000 or
> > 500.000 miles?... we have just now
> > mastered the solid state electrolyte and synthetic Graphene production. I
> > see now 500Wh/kg, >15 year lifetime
>
> I see someone arguing both sides of a fallacious argument.
>
> How can you criticize one manufacturer for unknown future problems who
> uses known technology, while lauding unknown technology for a long lifetime
> that none of it has even passed through?
>
> We have all sorts of empirical evidence with small cells. MTBF behaviour
> is well characterized. But there is absolutely NO empirical evidence for
> "15 year lifetime" of "solid state electrolyte and synthetic Graphene"
> cells.
>
> Personally, I prefer nickel-iron cells. But I'm an outlier. :-)
>
> Jan
>
>
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>
>
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Re: [EVDL] Large Format Cells vs. Small Format Cells for EVs

[Jukka Järvinen via EV]

You're absolutely right. Tesla has hired plenty of talent and they are
driving the cost down with vehicle designs. That said they cannot compete
in ESS with their existing design. They have now a chance as the grid side
compensations are pretty high and investments are paid back in about one
year. This is changing and the competition will be hard. The ESS business
is 100-fold compared to vehicles in next 20 years. The deployment rates are
very different as people have used to buy energy as a service but not yet
vehicle as a service. We do have the same issues with Utilities which are
comparable to OEM ICE. So this actually boils down to business models. Not
only superior technology. -Jukka



ma 10. syysk. 2018 klo 11.24 Michael Ross via EV (ev@lists.evdl.org)
kirjoitti:

> I believe Tesla has the best resources for developing batteries and
> manufacturing them.  They hired all the pertinent electrochemists at least.
> They have made themselves the subject matter experts, bar none.
>
> Also it is probable that for a while, new batteries designs will be
> manufactured in a similar manner, and Tesla will incur less capital outlay
> to retool than any new entries.
>
> Anyone with a better design would be smart to prove it to Tesla and get on
> board with them.  So far as we know, no one has demonstrated the efficacy
> of an any substantially new designs to them.
>
> An interesting point is that Tesla is not a typical for profit company.
> Musk at least will be happy to simply create a demand, and even
> competition.  The more successful the better. I have always kept this in
> mind when investing with them.  I actually think the battery business is
> more valuable than the car business.
>
> On Sun, Sep 9, 2018 at 10:14 PM robert winfield via EV 
> wrote:
>
> >  in 2018, so far Tesla has used 7,103,326 Kilowatt hours of batteries,
> 77%
> > of all the batteries used in EV's (less China) of the 9,279,755 total
> > It doesn't matter whether you argue prismatic or pouch or 18650 or
> > 2170. Tesla is outselling everyone else
> >
> > On Sunday, September 9, 2018, 8:45:20 PM EDT, ROBERT via EV <
> > ev@lists.evdl.org> wrote:
> >
> >  The problem with Tesla's batteries is not small vs large but Tesla has
> > put all their eggs into one type of battery.  The other automotive
> > companies are staying out of the battery business so that they can buy
> the
> > best batteries available and not spend money on development.  Vertical
> > business development is not always the best model.  At present, do what
> you
> > do best and assemble a final product and buy from numerous suppliers is
> the
> > current business model for the big automotive companies.
> >
> >
> > ____
> > From: EV  on behalf of Jan Steinman via EV <
> > ev@lists.evdl.org>
> > Sent: Sunday, September 9, 2018 10:02 AM
> > To: ev@lists.evdl.org
> > Cc: Jan Steinman
> > Subject: Re: [EVDL] Large Format Cells vs. Small Format Cells for EVs
> >
> > > From: Jukka J?rvinen 
> > >
> > > The main question is when will the problems be there? After 200.000 or
> > > 500.000 miles?... we have just now
> > > mastered the solid state electrolyte and synthetic Graphene
> production. I
> > > see now 500Wh/kg, >15 year lifetime
> >
> > I see someone arguing both sides of a fallacious argument.
> >
> > How can you criticize one manufacturer for unknown future problems who
> > uses known technology, while lauding unknown technology for a long
> lifetime
> > that none of it has even passed through?
> >
> > We have all sorts of empirical evidence with small cells. MTBF behaviour
> > is well characterized. But there is absolutely NO empirical evidence for
> > "15 year lifetime" of "solid state electrolyte and synthetic Graphene"
> > cells.
> >
> > Personally, I prefer nickel-iron cells. But I'm an outlier. :-)
> >
> > Jan
> >
> >
> > ___
> > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> > http://lists.evdl.org/listinfo.cgi/ev-evdl.org
> > Please discuss EV drag racing at NEDRA (
> > http://groups.yahoo.com/group/NEDRA)
> >
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> >
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> > >
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> > 

Re: [EVDL] Large Format Cells vs. Small Format Cells for EVs

[Jan Steinman via EV]

> From: George Tyler 
> 
> I used to design electronics for 
> military, (submarines) you can make MTBF say whatever you want!

Yea, so true. The Navy got so frustrated that they abandoned static analysis 
for real-time testing.

I worked on linear beam forming for subs. We used card-edge scan testing during 
retrace time, when the virtual beam was essentially scanning back through the 
hull. Each bus interface unit had a Motorola 68000 on it, just to control the 
testing, 60 times a second.

Jan

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Re: [EVDL] Large Format Cells vs. Small Format Cells for EVs

[Michael Ross via EV]

I believe Tesla has the best resources for developing batteries and
manufacturing them.  They hired all the pertinent electrochemists at least.
They have made themselves the subject matter experts, bar none.

Also it is probable that for a while, new batteries designs will be
manufactured in a similar manner, and Tesla will incur less capital outlay
to retool than any new entries.

Anyone with a better design would be smart to prove it to Tesla and get on
board with them.  So far as we know, no one has demonstrated the efficacy
of an any substantially new designs to them.

An interesting point is that Tesla is not a typical for profit company.
Musk at least will be happy to simply create a demand, and even
competition.  The more successful the better. I have always kept this in
mind when investing with them.  I actually think the battery business is
more valuable than the car business.

On Sun, Sep 9, 2018 at 10:14 PM robert winfield via EV 
wrote:

>  in 2018, so far Tesla has used 7,103,326 Kilowatt hours of batteries, 77%
> of all the batteries used in EV's (less China) of the 9,279,755 total
> It doesn't matter whether you argue prismatic or pouch or 18650 or
> 2170. Tesla is outselling everyone else
>
> On Sunday, September 9, 2018, 8:45:20 PM EDT, ROBERT via EV <
> ev@lists.evdl.org> wrote:
>
>  The problem with Tesla's batteries is not small vs large but Tesla has
> put all their eggs into one type of battery.  The other automotive
> companies are staying out of the battery business so that they can buy the
> best batteries available and not spend money on development.  Vertical
> business development is not always the best model.  At present, do what you
> do best and assemble a final product and buy from numerous suppliers is the
> current business model for the big automotive companies.
>
>
> 
> From: EV  on behalf of Jan Steinman via EV <
> ev@lists.evdl.org>
> Sent: Sunday, September 9, 2018 10:02 AM
> To: ev@lists.evdl.org
> Cc: Jan Steinman
> Subject: Re: [EVDL] Large Format Cells vs. Small Format Cells for EVs
>
> > From: Jukka J?rvinen 
> >
> > The main question is when will the problems be there? After 200.000 or
> > 500.000 miles?... we have just now
> > mastered the solid state electrolyte and synthetic Graphene production. I
> > see now 500Wh/kg, >15 year lifetime
>
> I see someone arguing both sides of a fallacious argument.
>
> How can you criticize one manufacturer for unknown future problems who
> uses known technology, while lauding unknown technology for a long lifetime
> that none of it has even passed through?
>
> We have all sorts of empirical evidence with small cells. MTBF behaviour
> is well characterized. But there is absolutely NO empirical evidence for
> "15 year lifetime" of "solid state electrolyte and synthetic Graphene"
> cells.
>
> Personally, I prefer nickel-iron cells. But I'm an outlier. :-)
>
> Jan
>
>
> ___
> UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
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> http://groups.yahoo.com/group/NEDRA)
>
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>
>

-- 
Michael E. Ross
(919) 585-6737 Land
(919) 901-2805 Cell and Text
(919) 576-0824 <https://www.google.com/voice/b/0?pli=1#phones> Tablet,
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Re: [EVDL] Large Format Cells vs. Small Format Cells for EVs

[robert winfield via EV]

 in 2018, so far Tesla has used 7,103,326 Kilowatt hours of batteries, 77% of 
all the batteries used in EV's (less China) of the 9,279,755 total
It doesn't matter whether you argue prismatic or pouch or 18650 or 2170. Tesla 
is outselling everyone else

On Sunday, September 9, 2018, 8:45:20 PM EDT, ROBERT via EV 
 wrote:  
 
 The problem with Tesla's batteries is not small vs large but Tesla has put all 
their eggs into one type of battery.  The other automotive companies are 
staying out of the battery business so that they can buy the best batteries 
available and not spend money on development.  Vertical business development is 
not always the best model.  At present, do what you do best and assemble a 
final product and buy from numerous suppliers is the current business model for 
the big automotive companies.



From: EV  on behalf of Jan Steinman via EV 

Sent: Sunday, September 9, 2018 10:02 AM
To: ev@lists.evdl.org
Cc: Jan Steinman
Subject: Re: [EVDL] Large Format Cells vs. Small Format Cells for EVs

> From: Jukka J?rvinen 
>
> The main question is when will the problems be there? After 200.000 or
> 500.000 miles?... we have just now
> mastered the solid state electrolyte and synthetic Graphene production. I
> see now 500Wh/kg, >15 year lifetime

I see someone arguing both sides of a fallacious argument.

How can you criticize one manufacturer for unknown future problems who uses 
known technology, while lauding unknown technology for a long lifetime that 
none of it has even passed through?

We have all sorts of empirical evidence with small cells. MTBF behaviour is 
well characterized. But there is absolutely NO empirical evidence for "15 year 
lifetime" of "solid state electrolyte and synthetic Graphene" cells.

Personally, I prefer nickel-iron cells. But I'm an outlier. :-)

Jan


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Re: [EVDL] Large Format Cells vs. Small Format Cells for EVs

[ROBERT via EV]

The problem with Tesla's batteries is not small vs large but Tesla has put all 
their eggs into one type of battery.  The other automotive companies are 
staying out of the battery business so that they can buy the best batteries 
available and not spend money on development.  Vertical business development is 
not always the best model.  At present, do what you do best and assemble a 
final product and buy from numerous suppliers is the current business model for 
the big automotive companies.



From: EV  on behalf of Jan Steinman via EV 

Sent: Sunday, September 9, 2018 10:02 AM
To: ev@lists.evdl.org
Cc: Jan Steinman
Subject: Re: [EVDL] Large Format Cells vs. Small Format Cells for EVs

> From: Jukka J?rvinen 
>
> The main question is when will the problems be there? After 200.000 or
> 500.000 miles?... we have just now
> mastered the solid state electrolyte and synthetic Graphene production. I
> see now 500Wh/kg, >15 year lifetime

I see someone arguing both sides of a fallacious argument.

How can you criticize one manufacturer for unknown future problems who uses 
known technology, while lauding unknown technology for a long lifetime that 
none of it has even passed through?

We have all sorts of empirical evidence with small cells. MTBF behaviour is 
well characterized. But there is absolutely NO empirical evidence for "15 year 
lifetime" of "solid state electrolyte and synthetic Graphene" cells.

Personally, I prefer nickel-iron cells. But I'm an outlier. :-)

Jan


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Re: [EVDL] Large Format Cells vs. Small Format Cells for EVs

[George Tyler via EV]

From a Electrical engineering perspective, the mean time between 
failures of 6800 cells is terrible but you can lose a lot and still have 
a functioning car, so I recon he is probably right, but it depends of 
the MTBF of the 2 types of cells too. I used to design electronics for 
military, (submarines) you can make MTBF say whatever you want! nowdays 
they use FMEA (failure mode and effects analysis) too, that this would 
show what really happens.
 you could say "if you lose one cell with large format then the car 
is immobilized but you could lose 3400 cells with small format, so it's 
3400 times better".




On 09-Sep-18 1:34 PM, mark hanson via EV wrote:

Hi Bob etc,

  


Consumer Reports said while they loved driving a Tesla model S, they gave it
a poor rating on reliability and preferred the Leaf and now the Bolt, saying
"you'd be nuts not to consider a Bolt".  Elon Musk/Tesla is the *only*
company that's putting 6800+ 21mm X 70mm itty bitty cells together in a
large EV.  When they came out with the Roadster in California, I asked a
Tesla salesman about the long term reliability of 6800 points of failure and
he said "don't think of it as 6800 points of failure, think of it as 6800
points of redundancy".  Good spin.  Either they know something that *no*
other large scale vehicle manufacturer/engineering teams doesn't, or their
long term reliability/profitability will continue to be poor.  Knowing what
I know about electronic componentry, I'll put my money on large format cells
for large on road EV's, Bolt, Leaf, Smart, BMW etc.

  


Note for further info, see: www.Batteryuniversity.com EV battery
comparisons/lithium chemistries LMC Cathode, vs LiFePO4 & aluminized cathode
(tesla type) cells.

  


Best regards,

Mark




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Re: [EVDL] Large Format Cells vs. Small Format Cells for EVs

[Bobby Keeland via EV]

The comments below about the reliability of Tesla I have heard from
numerous people. The refusal of Nissan to take responsibility of problems
is a personal experience of mine.
Bob Keeland, PhD

On Sun, Sep 9, 2018, 3:49 PM Willie via EV  wrote:

>
>
> On 09/08/2018 09:38 PM, Peri Hartman via EV wrote:
> > Well, does anyone have actual numbers regarding failures of Teslas?
> > Overall, they've been out long enough that "we" should know if there are
> > reliability problems or not. On my part, I have not heard of any
> > widespread Tesla failure. What reliability problems is C.S. referring to?
>
> Anecdotal, but I know of quite of few Ss that have had their batteries
> replaced/repaired in warranty.  On my ~130k mile 2013 S, the battery was
> recently changed.  There was no real obvious issue but the Tesla service
> people said it should be changed.  Range was still above 90% of original
> and I had not complained of range loss; I considered the loss
> reasonable.  I would guess 30-50% of Tesla with more than 100k miles
> have had their batteries replaced.  Probably all under warranty; I have
> heard of no one who had to buy a battery.  Fact is, cost of replacement
> in generally unknown.  It seems Tesla is not replacing with new
> batteries.  In some cases they install a loaner battery while the faulty
> battery is being refurbished.  In other cases they replace with a
> refurbished battery.   I assume the refurbishment involves replacing a
> smallish number of bad cells.
>
> Much in contrast to Nissan, the battery replacements are painless; as
> mentioned, I did not even know I had a battery problem but Tesla was
> eager to make it right.  Nissan refuses to replace obviously bad batteries.
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Re: [EVDL] Large Format Cells vs. Small Format Cells for EVs

[Michael Ross via EV]

500kWh/kg is really game changing. Musk estimated (quite a long time ago
now) that 400kWh/kg would be the threshold for economical supersonic air
transport.

On Sun, Sep 9, 2018 at 7:19 AM Jukka Järvinen via EV 
wrote:

> Hi guys.
>
> Since tZero the small-cell-paralleling has been driven by costs and the
> search for benefit of scale. During those days there were not so many
> ”large” cell format producers and the cost efficiency was not even close to
> laptop cells. We were even looking in all kind of folding methods and
> stacking techiques back then. A lot of trial and error was still ahead.
>
> Why small cell paralleling has an issue which will eventually render to
> problems?
>
> Because cells age differently due plenty of different factors. If they have
> fuses for their max C rate and one parallels them the current is wobbling
> around between each cell unevenly. More they age more they wobble. Current
> goes through where is the most lowest resistance. The fuse blows when in
> high current situation the best cell tries to compensate the weak ones.
> Once fuse is blown all work is done by the rest of the cells (which were
> the bad ones already). This repeats until there is only few fuses left and
> you’re on turtle mode.
>
> ”Large” format cells have less fuses as they have the same chemical mass as
> maybe 10 or 15 small cells. Paralleling two or three cells one can fuse
> with more relaxed sizing. Using actual large cells (>300Ah) one fuse (if
> any) is enough.
>
> The trend is more stable chemistry cells can grow even bigger. 10.000Ah
> cells have been demostrated with LiFePO4. And no fuses.
>
> Tesla and many other small cells users put a lot of effort to distribute
> the heat as evenly as possible. This gives a lot of more time to avoid
> cascade effect with blowing fuses. But this is the Modus Operandi for EOL.
> It will happen. Not if.
>
> Now. The main question is when will the problems be there? After 200.000 or
> 500.000 miles? Maybe one million miles? We are already at the point where
> this does not matter. So Tesla design is very good as it is ”good enough”
> and provides what it needs to. It all boils down to their cell production
> and sorting methods. Or if they design an adaptive fusing setup.
>
> The major change is still coming to the industry as we have just now
> mastered the solid state electrolyte and synthetic Graphene production. I
> see now 500Wh/kg, >15 year lifetime and <$50/kWh in my horizon. We are now
> already living an industrial disruption. Ejoy the (electrical) ride!
>
> -Jukka
>
>
> su 9.9.2018 klo 12.54 mark hanson via EV  kirjoitti:
>
> > Hi Bob etc,
> >
> >
> >
> > Consumer Reports said while they loved driving a Tesla model S, they gave
> > it
> > a poor rating on reliability and preferred the Leaf and now the Bolt,
> > saying
> > "you'd be nuts not to consider a Bolt".  Elon Musk/Tesla is the *only*
> > company that's putting 6800+ 21mm X 70mm itty bitty cells together in a
> > large EV.  When they came out with the Roadster in California, I asked a
> > Tesla salesman about the long term reliability of 6800 points of failure
> > and
> > he said "don't think of it as 6800 points of failure, think of it as 6800
> > points of redundancy".  Good spin.  Either they know something that *no*
> > other large scale vehicle manufacturer/engineering teams doesn't, or
> their
> > long term reliability/profitability will continue to be poor.  Knowing
> what
> > I know about electronic componentry, I'll put my money on large format
> > cells
> > for large on road EV's, Bolt, Leaf, Smart, BMW etc.
> >
> >
> >
> > Note for further info, see: www.Batteryuniversity.com EV battery
> > comparisons/lithium chemistries LMC Cathode, vs LiFePO4 & aluminized
> > cathode
> > (tesla type) cells.
> >
> >
> >
> > Best regards,
> >
> > Mark
> >
> >
> >
> >
> >
> > Date: Fri, 7 Sep 2018 18:00:28 -0400
> >
> > From: Robert Bruninga 
> >
> > To: Electric Vehicle Discussion List 
> >
> > Subject: Re: [EVDL] Fwd: A comparative efficiency study of ... now
> >
> >   Redundancy!
> >
> > Message-ID: 
> >
> > Content-Type: text/plain; charset="UTF-8"
> >
> >
> >
> > > I've always had it beat into my pointy engineering head  to minimize
> >
> > > component count. Which is also why  id never own a Tesla with 6800 or
> >
> > > so cells in their battery.
> >
> >
> >
> > That philosophy fails to recognize the value gained in multiple
> redundancy.
> >
> > The Tesla battery of 6800 cells is far more reliable since it has 74
> cells
> > in PARALLEL for each 3.6volt lithium unit.  Compared to a Leaf with only
> 2
> > cells in parallel at each stage in the stack.
> >
> >
> >
> > IN the Tesla the impact on any single battery failure is then only 3% of
> > the
> > impact of a cell problem on a car with larger format cells.
> >
> >
> >
> > I'd take the multiple redundancy of the Tesla any day.
> >
> >
> >
> > Bob
> >
> >
> >
> >
> >
> > -- next part --
> > An HTML attachment was 

Re: [EVDL] Large Format Cells vs. Small Format Cells for EVs

[Paul Dove via EV]

Oh yea, his premise is wrong as well. A large format cell is made up of many 
smaller cells in parallel. I opened a 100 Ah cell and it had 10 - 10Ah cells 
paralleled inside with no fuse between them: so if you loose one you loose them 
all.

Sent from my iPad

> On Sep 9, 2018, at 6:24 AM, Willie via EV  wrote:
> 
> 
> 
>> On 09/08/2018 09:38 PM, Peri Hartman via EV wrote:
>> Well, does anyone have actual numbers regarding failures of Teslas? Overall, 
>> they've been out long enough that "we" should know if there are reliability 
>> problems or not. On my part, I have not heard of any widespread Tesla 
>> failure. What reliability problems is C.S. referring to?
> 
> Anecdotal, but I know of quite of few Ss that have had their batteries 
> replaced/repaired in warranty.  On my ~130k mile 2013 S, the battery was 
> recently changed.  There was no real obvious issue but the Tesla service 
> people said it should be changed.  Range was still above 90% of original and 
> I had not complained of range loss; I considered the loss reasonable.  I 
> would guess 30-50% of Tesla with more than 100k miles have had their 
> batteries replaced.  Probably all under warranty; I have heard of no one who 
> had to buy a battery.  Fact is, cost of replacement in generally unknown.  It 
> seems Tesla is not replacing with new batteries.  In some cases they install 
> a loaner battery while the faulty battery is being refurbished.  In other 
> cases they replace with a refurbished battery.   I assume the refurbishment 
> involves replacing a smallish number of bad cells.
> 
> Much in contrast to Nissan, the battery replacements are painless; as 
> mentioned, I did not even know I had a battery problem but Tesla was eager to 
> make it right.  Nissan refuses to replace obviously bad batteries.
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Re: [EVDL] Large Format Cells vs. Small Format Cells for EVs

[Jan Steinman via EV]

> From: Jukka J?rvinen 
> 
> The main question is when will the problems be there? After 200.000 or
> 500.000 miles?... we have just now
> mastered the solid state electrolyte and synthetic Graphene production. I
> see now 500Wh/kg, >15 year lifetime 

I see someone arguing both sides of a fallacious argument.

How can you criticize one manufacturer for unknown future problems who uses 
known technology, while lauding unknown technology for a long lifetime that 
none of it has even passed through?

We have all sorts of empirical evidence with small cells. MTBF behaviour is 
well characterized. But there is absolutely NO empirical evidence for "15 year 
lifetime" of "solid state electrolyte and synthetic Graphene" cells.

Personally, I prefer nickel-iron cells. But I'm an outlier. :-)

Jan


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Re: [EVDL] Large Format Cells vs. Small Format Cells for EVs

[paul dove via EV]

I know Tesla had problems with there gear box early on but I have heard of no 
battery issues. And since when is a bolt a lot less than a Tesla? My Tesla was 
41000 that’s right in there with a bolt aren’t they ~37000?

Sent from my iPhone

> On Sep 8, 2018, at 9:38 PM, Peri Hartman via EV  wrote:
> 
> Well, does anyone have actual numbers regarding failures of Teslas? Overall, 
> they've been out long enough that "we" should know if there are reliability 
> problems or not. On my part, I have not heard of any widespread Tesla 
> failure. What reliability problems is C.S. referring to?
> 
> As for C.S. other statement, I would agree one would be nuts not to consider 
> a Bolt. For a lot less money you get a great car. That doesn't say anything 
> bad about a Tesla, though.
> 
> Peri
> 
> -- Original Message --
> From: "mark hanson via EV" 
> To: "'Electric Vehicle Discussion List'" 
> Cc: "mark hanson" 
> Sent: 08-Sep-18 6:34:24 PM
> Subject: [EVDL] Large Format Cells vs. Small Format Cells for EVs
> 
>> Hi Bob etc,
>> 
>> 
>> 
>> Consumer Reports said while they loved driving a Tesla model S, they gave it
>> a poor rating on reliability and preferred the Leaf and now the Bolt, saying
>> "you'd be nuts not to consider a Bolt".  Elon Musk/Tesla is the *only*
>> company that's putting 6800+ 21mm X 70mm itty bitty cells together in a
>> large EV.  When they came out with the Roadster in California, I asked a
>> Tesla salesman about the long term reliability of 6800 points of failure and
>> he said "don't think of it as 6800 points of failure, think of it as 6800
>> points of redundancy".  Good spin.  Either they know something that *no*
>> other large scale vehicle manufacturer/engineering teams doesn't, or their
>> long term reliability/profitability will continue to be poor.  Knowing what
>> I know about electronic componentry, I'll put my money on large format cells
>> for large on road EV's, Bolt, Leaf, Smart, BMW etc.
>> 
>> 
>> 
>> Note for further info, see: www.Batteryuniversity.com EV battery
>> comparisons/lithium chemistries LMC Cathode, vs LiFePO4 & aluminized cathode
>> (tesla type) cells.
>> 
>> 
>> 
>> Best regards,
>> 
>> Mark
>> 
>> 
>> 
>> 
>> 
>> Date: Fri, 7 Sep 2018 18:00:28 -0400
>> 
>> From: Robert Bruninga 
>> 
>> To: Electric Vehicle Discussion List 
>> 
>> Subject: Re: [EVDL] Fwd: A comparative efficiency study of ... now
>> 
>> Redundancy!
>> 
>> Message-ID: 
>> 
>> Content-Type: text/plain; charset="UTF-8"
>> 
>> 
>> 
>>> I've always had it beat into my pointy engineering head  to minimize
>> 
>>> component count. Which is also why  id never own a Tesla with 6800 or
>> 
>>> so cells in their battery.
>> 
>> 
>> 
>> That philosophy fails to recognize the value gained in multiple redundancy.
>> 
>> The Tesla battery of 6800 cells is far more reliable since it has 74 cells
>> in PARALLEL for each 3.6volt lithium unit.  Compared to a Leaf with only 2
>> cells in parallel at each stage in the stack.
>> 
>> 
>> 
>> IN the Tesla the impact on any single battery failure is then only 3% of the
>> impact of a cell problem on a car with larger format cells.
>> 
>> 
>> 
>> I'd take the multiple redundancy of the Tesla any day.
>> 
>> 
>> 
>> Bob
>> 
>> 
>> 
>> 
>> 
>> -- next part --
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>> 
> 
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Re: [EVDL] Large Format Cells vs. Small Format Cells for EVs

[Willie via EV]

On 09/08/2018 09:38 PM, Peri Hartman via EV wrote:
Well, does anyone have actual numbers regarding failures of Teslas? 
Overall, they've been out long enough that "we" should know if there are 
reliability problems or not. On my part, I have not heard of any 
widespread Tesla failure. What reliability problems is C.S. referring to?


Anecdotal, but I know of quite of few Ss that have had their batteries 
replaced/repaired in warranty.  On my ~130k mile 2013 S, the battery was 
recently changed.  There was no real obvious issue but the Tesla service 
people said it should be changed.  Range was still above 90% of original 
and I had not complained of range loss; I considered the loss 
reasonable.  I would guess 30-50% of Tesla with more than 100k miles 
have had their batteries replaced.  Probably all under warranty; I have 
heard of no one who had to buy a battery.  Fact is, cost of replacement 
in generally unknown.  It seems Tesla is not replacing with new 
batteries.  In some cases they install a loaner battery while the faulty 
battery is being refurbished.  In other cases they replace with a 
refurbished battery.   I assume the refurbishment involves replacing a 
smallish number of bad cells.


Much in contrast to Nissan, the battery replacements are painless; as 
mentioned, I did not even know I had a battery problem but Tesla was 
eager to make it right.  Nissan refuses to replace obviously bad batteries.

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Re: [EVDL] Large Format Cells vs. Small Format Cells for EVs

[Cor van de Water via EV]

Mark,
I think it is a fallacy to consider all large format cells as single point
of failure, the prismatic cells that i have seen opened all consisted of
multiple cells internally, sometimes several dozen thin pouch cells with
their terminals clamped together, for example 20 cells of 5Ah stuffed in
one plastic housing to create a single 100Ah cell. So, i see this as an
addition of 20 points of failure *without* redundancy, because unlike Tesla
which uses cell level fuses, the concept of bolted together cells causes a
big failure if a single cell shorts.
I have discovered in an unexplicable EV fire in a vehicle that was not
charging, that where the fire started, there was the remnants of one
prismatic cell in particular that apparently one pouch was folded double
when initially constructing the cell out of a stack of pouches. As we all
know, pouches swell in use, so i think that was a mfg error and a failure
waiting to happen and because a multitude of paralleled pouches a dump
their energy into a single failing pouch due to this parallel construction,
causing a chain reaction where first a single pouch overheats and catches
fire, then ignites the other pouches in the same cell and when the cell
walls are breached by the fire or explosion if pressure gets out of hand,
then the adjacent cells go the same way.
I rather see a single failing point result in a blown fuse and a few
percent of capacity reduction, because the cells are constructed in a way
that a single cell failure does not spread beyond that cell.

To be honest, i have never seen a failure that propagated in a Nissan Leaf
pack, despite their choice to parallel two pouches in every module.

Regards,
Cor.

On Sun, Sep 9, 2018, 3:54 AM mark hanson via EV  wrote:

> Hi Bob etc,
>
>
>
> Consumer Reports said while they loved driving a Tesla model S, they gave
> it
> a poor rating on reliability and preferred the Leaf and now the Bolt,
> saying
> "you'd be nuts not to consider a Bolt".  Elon Musk/Tesla is the *only*
> company that's putting 6800+ 21mm X 70mm itty bitty cells together in a
> large EV.  When they came out with the Roadster in California, I asked a
> Tesla salesman about the long term reliability of 6800 points of failure
> and
> he said "don't think of it as 6800 points of failure, think of it as 6800
> points of redundancy".  Good spin.  Either they know something that *no*
> other large scale vehicle manufacturer/engineering teams doesn't, or their
> long term reliability/profitability will continue to be poor.  Knowing what
> I know about electronic componentry, I'll put my money on large format
> cells
> for large on road EV's, Bolt, Leaf, Smart, BMW etc.
>
>
>
> Note for further info, see: www.Batteryuniversity.com EV battery
> comparisons/lithium chemistries LMC Cathode, vs LiFePO4 & aluminized
> cathode
> (tesla type) cells.
>
>
>
> Best regards,
>
> Mark
>
>
>
>
>
> Date: Fri, 7 Sep 2018 18:00:28 -0400
>
> From: Robert Bruninga 
>
> To: Electric Vehicle Discussion List 
>
> Subject: Re: [EVDL] Fwd: A comparative efficiency study of ... now
>
>   Redundancy!
>
> Message-ID: 
>
> Content-Type: text/plain; charset="UTF-8"
>
>
>
> > I've always had it beat into my pointy engineering head  to minimize
>
> > component count. Which is also why  id never own a Tesla with 6800 or
>
> > so cells in their battery.
>
>
>
> That philosophy fails to recognize the value gained in multiple redundancy.
>
> The Tesla battery of 6800 cells is far more reliable since it has 74 cells
> in PARALLEL for each 3.6volt lithium unit.  Compared to a Leaf with only 2
> cells in parallel at each stage in the stack.
>
>
>
> IN the Tesla the impact on any single battery failure is then only 3% of
> the
> impact of a cell problem on a car with larger format cells.
>
>
>
> I'd take the multiple redundancy of the Tesla any day.
>
>
>
> Bob
>
>
>
>
>
> -- next part --
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Re: [EVDL] Large Format Cells vs. Small Format Cells for EVs

[Jukka Järvinen via EV]

Hi guys.

Since tZero the small-cell-paralleling has been driven by costs and the
search for benefit of scale. During those days there were not so many
”large” cell format producers and the cost efficiency was not even close to
laptop cells. We were even looking in all kind of folding methods and
stacking techiques back then. A lot of trial and error was still ahead.

Why small cell paralleling has an issue which will eventually render to
problems?

Because cells age differently due plenty of different factors. If they have
fuses for their max C rate and one parallels them the current is wobbling
around between each cell unevenly. More they age more they wobble. Current
goes through where is the most lowest resistance. The fuse blows when in
high current situation the best cell tries to compensate the weak ones.
Once fuse is blown all work is done by the rest of the cells (which were
the bad ones already). This repeats until there is only few fuses left and
you’re on turtle mode.

”Large” format cells have less fuses as they have the same chemical mass as
maybe 10 or 15 small cells. Paralleling two or three cells one can fuse
with more relaxed sizing. Using actual large cells (>300Ah) one fuse (if
any) is enough.

The trend is more stable chemistry cells can grow even bigger. 10.000Ah
cells have been demostrated with LiFePO4. And no fuses.

Tesla and many other small cells users put a lot of effort to distribute
the heat as evenly as possible. This gives a lot of more time to avoid
cascade effect with blowing fuses. But this is the Modus Operandi for EOL.
It will happen. Not if.

Now. The main question is when will the problems be there? After 200.000 or
500.000 miles? Maybe one million miles? We are already at the point where
this does not matter. So Tesla design is very good as it is ”good enough”
and provides what it needs to. It all boils down to their cell production
and sorting methods. Or if they design an adaptive fusing setup.

The major change is still coming to the industry as we have just now
mastered the solid state electrolyte and synthetic Graphene production. I
see now 500Wh/kg, >15 year lifetime and <$50/kWh in my horizon. We are now
already living an industrial disruption. Ejoy the (electrical) ride!

-Jukka


su 9.9.2018 klo 12.54 mark hanson via EV  kirjoitti:

> Hi Bob etc,
>
>
>
> Consumer Reports said while they loved driving a Tesla model S, they gave
> it
> a poor rating on reliability and preferred the Leaf and now the Bolt,
> saying
> "you'd be nuts not to consider a Bolt".  Elon Musk/Tesla is the *only*
> company that's putting 6800+ 21mm X 70mm itty bitty cells together in a
> large EV.  When they came out with the Roadster in California, I asked a
> Tesla salesman about the long term reliability of 6800 points of failure
> and
> he said "don't think of it as 6800 points of failure, think of it as 6800
> points of redundancy".  Good spin.  Either they know something that *no*
> other large scale vehicle manufacturer/engineering teams doesn't, or their
> long term reliability/profitability will continue to be poor.  Knowing what
> I know about electronic componentry, I'll put my money on large format
> cells
> for large on road EV's, Bolt, Leaf, Smart, BMW etc.
>
>
>
> Note for further info, see: www.Batteryuniversity.com EV battery
> comparisons/lithium chemistries LMC Cathode, vs LiFePO4 & aluminized
> cathode
> (tesla type) cells.
>
>
>
> Best regards,
>
> Mark
>
>
>
>
>
> Date: Fri, 7 Sep 2018 18:00:28 -0400
>
> From: Robert Bruninga 
>
> To: Electric Vehicle Discussion List 
>
> Subject: Re: [EVDL] Fwd: A comparative efficiency study of ... now
>
>   Redundancy!
>
> Message-ID: 
>
> Content-Type: text/plain; charset="UTF-8"
>
>
>
> > I've always had it beat into my pointy engineering head  to minimize
>
> > component count. Which is also why  id never own a Tesla with 6800 or
>
> > so cells in their battery.
>
>
>
> That philosophy fails to recognize the value gained in multiple redundancy.
>
> The Tesla battery of 6800 cells is far more reliable since it has 74 cells
> in PARALLEL for each 3.6volt lithium unit.  Compared to a Leaf with only 2
> cells in parallel at each stage in the stack.
>
>
>
> IN the Tesla the impact on any single battery failure is then only 3% of
> the
> impact of a cell problem on a car with larger format cells.
>
>
>
> I'd take the multiple redundancy of the Tesla any day.
>
>
>
> Bob
>
>
>
>
>
> -- next part --
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Re: [EVDL] Large Format Cells vs. Small Format Cells for EVs

[Peri Hartman via EV]

Well, does anyone have actual numbers regarding failures of Teslas? 
Overall, they've been out long enough that "we" should know if there are 
reliability problems or not. On my part, I have not heard of any 
widespread Tesla failure. What reliability problems is C.S. referring 
to?


As for C.S. other statement, I would agree one would be nuts not to 
consider a Bolt. For a lot less money you get a great car. That doesn't 
say anything bad about a Tesla, though.


Peri

-- Original Message --
From: "mark hanson via EV" 
To: "'Electric Vehicle Discussion List'" 
Cc: "mark hanson" 
Sent: 08-Sep-18 6:34:24 PM
Subject: [EVDL] Large Format Cells vs. Small Format Cells for EVs


Hi Bob etc,



Consumer Reports said while they loved driving a Tesla model S, they 
gave it
a poor rating on reliability and preferred the Leaf and now the Bolt, 
saying

"you'd be nuts not to consider a Bolt".  Elon Musk/Tesla is the *only*
company that's putting 6800+ 21mm X 70mm itty bitty cells together in a
large EV.  When they came out with the Roadster in California, I asked 
a
Tesla salesman about the long term reliability of 6800 points of 
failure and
he said "don't think of it as 6800 points of failure, think of it as 
6800
points of redundancy".  Good spin.  Either they know something that 
*no*
other large scale vehicle manufacturer/engineering teams doesn't, or 
their
long term reliability/profitability will continue to be poor.  Knowing 
what
I know about electronic componentry, I'll put my money on large format 
cells

for large on road EV's, Bolt, Leaf, Smart, BMW etc.



Note for further info, see: www.Batteryuniversity.com EV battery
comparisons/lithium chemistries LMC Cathode, vs LiFePO4 & aluminized 
cathode

(tesla type) cells.



Best regards,

Mark





Date: Fri, 7 Sep 2018 18:00:28 -0400

From: Robert Bruninga 

To: Electric Vehicle Discussion List 

Subject: Re: [EVDL] Fwd: A comparative efficiency study of ... now

 Redundancy!

Message-ID: 

Content-Type: text/plain; charset="UTF-8"




I've always had it beat into my pointy engineering head  to minimize



component count. Which is also why  id never own a Tesla with 6800 or



so cells in their battery.




That philosophy fails to recognize the value gained in multiple 
redundancy.


The Tesla battery of 6800 cells is far more reliable since it has 74 
cells
in PARALLEL for each 3.6volt lithium unit.  Compared to a Leaf with 
only 2

cells in parallel at each stage in the stack.



IN the Tesla the impact on any single battery failure is then only 3% 
of the

impact of a cell problem on a car with larger format cells.



I'd take the multiple redundancy of the Tesla any day.



Bob





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[EVDL] Large Format Cells vs. Small Format Cells for EVs

[mark hanson via EV]

Hi Bob etc,

 

Consumer Reports said while they loved driving a Tesla model S, they gave it
a poor rating on reliability and preferred the Leaf and now the Bolt, saying
"you'd be nuts not to consider a Bolt".  Elon Musk/Tesla is the *only*
company that's putting 6800+ 21mm X 70mm itty bitty cells together in a
large EV.  When they came out with the Roadster in California, I asked a
Tesla salesman about the long term reliability of 6800 points of failure and
he said "don't think of it as 6800 points of failure, think of it as 6800
points of redundancy".  Good spin.  Either they know something that *no*
other large scale vehicle manufacturer/engineering teams doesn't, or their
long term reliability/profitability will continue to be poor.  Knowing what
I know about electronic componentry, I'll put my money on large format cells
for large on road EV's, Bolt, Leaf, Smart, BMW etc.  

 

Note for further info, see: www.Batteryuniversity.com EV battery
comparisons/lithium chemistries LMC Cathode, vs LiFePO4 & aluminized cathode
(tesla type) cells.

 

Best regards,

Mark

 

 

Date: Fri, 7 Sep 2018 18:00:28 -0400

From: Robert Bruninga 

To: Electric Vehicle Discussion List 

Subject: Re: [EVDL] Fwd: A comparative efficiency study of ... now

  Redundancy!

Message-ID: 

Content-Type: text/plain; charset="UTF-8"

 

> I've always had it beat into my pointy engineering head  to minimize 

> component count. Which is also why  id never own a Tesla with 6800 or 

> so cells in their battery.

 

That philosophy fails to recognize the value gained in multiple redundancy.

The Tesla battery of 6800 cells is far more reliable since it has 74 cells
in PARALLEL for each 3.6volt lithium unit.  Compared to a Leaf with only 2
cells in parallel at each stage in the stack.

 

IN the Tesla the impact on any single battery failure is then only 3% of the
impact of a cell problem on a car with larger format cells.

 

I'd take the multiple redundancy of the Tesla any day.

 

Bob

 

 

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