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 4:4
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
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
Sub
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
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,
pr
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
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 con
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 d
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 gu
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 yea
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 p
> 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 l
t
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
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 importa
del. 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
> 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 test
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.o
n 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
unday, 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
> mast
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, (subma
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 wro
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
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
> 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 fallacio
; 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,
>>
>>
>>
&g
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 reli
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
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
s
icle 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
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
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