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 <[hidden email]> To: Electric Vehicle Discussion List <[hidden email]> Subject: Re: [EVDL] Fwd: A comparative efficiency study of ... now Redundancy! Message-ID: <[hidden email]> 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 scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20180908/dc82f936/attachment.html> _______________________________________________ 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) |
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" <[hidden email]> To: "'Electric Vehicle Discussion List'" <[hidden email]> Cc: "mark hanson" <[hidden email]> 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 <[hidden email]> > >To: Electric Vehicle Discussion List <[hidden email]> > >Subject: Re: [EVDL] Fwd: A comparative efficiency study of ... now > > Redundancy! > >Message-ID: <[hidden email]> > >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 scrubbed... >URL: ><http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20180908/dc82f936/attachment.html> >_______________________________________________ >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) > _______________________________________________ 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) |
In reply to this post by Electric Vehicle Discussion List mailing list
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 <[hidden email]> 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 <[hidden email]> > > To: Electric Vehicle Discussion List <[hidden email]> > > Subject: Re: [EVDL] Fwd: A comparative efficiency study of ... now > > Redundancy! > > Message-ID: <[hidden email]> > > 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 scrubbed... > URL: < > http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20180908/dc82f936/attachment.html > > > _______________________________________________ > 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) > > An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20180909/925cf394/attachment.html> _______________________________________________ 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) |
In reply to this post by Electric Vehicle Discussion List mailing list
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 <[hidden email]> 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 <[hidden email]> > > To: Electric Vehicle Discussion List <[hidden email]> > > Subject: Re: [EVDL] Fwd: A comparative efficiency study of ... now > > Redundancy! > > Message-ID: <[hidden email]> > > 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 scrubbed... > URL: < > http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20180908/dc82f936/attachment.html > > > _______________________________________________ > 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) > > An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20180909/bbf6178f/attachment.html> _______________________________________________ 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) |
In reply to this post by Electric Vehicle Discussion List mailing list
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. _______________________________________________ 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) |
In reply to this post by Electric Vehicle Discussion List mailing list
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 <[hidden email]> 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" <[hidden email]> > To: "'Electric Vehicle Discussion List'" <[hidden email]> > Cc: "mark hanson" <[hidden email]> > 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 <[hidden email]> >> >> To: Electric Vehicle Discussion List <[hidden email]> >> >> Subject: Re: [EVDL] Fwd: A comparative efficiency study of ... now >> >> Redundancy! >> >> Message-ID: <[hidden email]> >> >> 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 scrubbed... >> URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20180908/dc82f936/attachment.html> >> _______________________________________________ >> 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) >> > > _______________________________________________ > 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) > _______________________________________________ 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) |
In reply to this post by Electric Vehicle Discussion List mailing list
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 <[hidden email]> 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. > _______________________________________________ > 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) > _______________________________________________ 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) |
In reply to this post by Electric Vehicle Discussion List mailing list
> From: Jukka J?rvinen <[hidden email]>
> > 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) |
In reply to this post by Electric Vehicle Discussion List mailing list
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 <[hidden email]> 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 <[hidden email]> 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 <[hidden email]> > > > > To: Electric Vehicle Discussion List <[hidden email]> > > > > Subject: Re: [EVDL] Fwd: A comparative efficiency study of ... now > > > > Redundancy! > > > > Message-ID: <[hidden email]> > > > > 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 scrubbed... > > URL: < > > > http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20180908/dc82f936/attachment.html > > > > > _______________________________________________ > > 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) > > > > > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: < > http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20180909/925cf394/attachment.html > > > _______________________________________________ > 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) > > -- 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, Google Phone and Text -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20180909/f6d8dae5/attachment.html> _______________________________________________ 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) |
In reply to this post by Electric Vehicle Discussion List mailing list
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 <[hidden email]> 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. > _______________________________________________ > 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) > > An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20180909/a610c35d/attachment.html> _______________________________________________ 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) |
In reply to this post by Electric Vehicle Discussion List mailing list
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 <[hidden email]> on behalf of Jan Steinman via EV <[hidden email]> Sent: Sunday, September 9, 2018 10:02 AM To: [hidden email] Cc: Jan Steinman Subject: Re: [EVDL] Large Format Cells vs. Small Format Cells for EVs > From: Jukka J?rvinen <[hidden email]> > > 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) -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20180909/603a0d9b/attachment.html> _______________________________________________ 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) |
In reply to this post by Electric Vehicle Discussion List mailing list
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 > > _______________________________________________ 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) |
In reply to this post by Electric Vehicle Discussion List mailing list
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 <[hidden email]> 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 <[hidden email]> on behalf of Jan Steinman via EV <[hidden email]> Sent: Sunday, September 9, 2018 10:02 AM To: [hidden email] Cc: Jan Steinman Subject: Re: [EVDL] Large Format Cells vs. Small Format Cells for EVs > From: Jukka J?rvinen <[hidden email]> > > 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) -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20180909/603a0d9b/attachment.html> _______________________________________________ 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) -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20180910/c2dd37dc/attachment.html> _______________________________________________ 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) |
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 <[hidden email]> 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 < > [hidden email]> 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 <[hidden email]> on behalf of Jan Steinman via EV < > [hidden email]> > Sent: Sunday, September 9, 2018 10:02 AM > To: [hidden email] > Cc: Jan Steinman > Subject: Re: [EVDL] Large Format Cells vs. Small Format Cells for EVs > > > From: Jukka J?rvinen <[hidden email]> > > > > 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) > > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: < > http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20180909/603a0d9b/attachment.html > > > _______________________________________________ > 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) > > > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: < > http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20180910/c2dd37dc/attachment.html > > > _______________________________________________ > 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) > > -- 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, Google Phone and Text -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20180909/883f9aa0/attachment.html> _______________________________________________ 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) |
In reply to this post by Electric Vehicle Discussion List mailing list
> From: George Tyler <[hidden email]>
> > 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 _______________________________________________ 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) |
In reply to this post by Electric Vehicle Discussion List mailing list
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 ([hidden email]) 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 <[hidden email]> > 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 < > > [hidden email]> 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 <[hidden email]> on behalf of Jan Steinman via EV < > > [hidden email]> > > Sent: Sunday, September 9, 2018 10:02 AM > > To: [hidden email] > > Cc: Jan Steinman > > Subject: Re: [EVDL] Large Format Cells vs. Small Format Cells for EVs > > > > > From: Jukka J?rvinen <[hidden email]> > > > > > > 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) > > > > -------------- next part -------------- > > An HTML attachment was scrubbed... > > URL: < > > > http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20180909/603a0d9b/attachment.html > > > > > _______________________________________________ > > 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) > > > > > > -------------- next part -------------- > > An HTML attachment was scrubbed... > > URL: < > > > http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20180910/c2dd37dc/attachment.html > > > > > _______________________________________________ > > 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) > > > > > > -- > 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, > Google Phone and Text > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: < > http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20180909/883f9aa0/attachment.html > > > _______________________________________________ > 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) > > An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20180910/5d65bb05/attachment.html> _______________________________________________ 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) |
In reply to this post by Electric Vehicle Discussion List mailing list
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 ([hidden email]) kirjoitti: > > From: Jukka J?rvinen <[hidden email]> > > > > 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) > > An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20180910/3ba85d7f/attachment.html> _______________________________________________ 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) |
In reply to this post by Electric Vehicle Discussion List mailing list
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:[hidden email]] On Behalf Of Jan Steinman via EV Sent: 10 September, 2018 4:47 PM To: [hidden email] Cc: Jan Steinman Subject: Re: [EVDL] Large Format Cells vs. Small Format Cells for EVs > From: George Tyler <[hidden email]> > > 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 _______________________________________________ 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) _______________________________________________ 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) |
In reply to this post by Electric Vehicle Discussion List mailing list
> From: "George Tyler" <[hidden email]>
> > 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 _______________________________________________ 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) |
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 10000 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 10000 cycles. On Tue, Sep 11, 2018 at 7:04 PM Jan Steinman via EV <[hidden email]> wrote: > > From: "George Tyler" <[hidden email]> > > > > 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 > > _______________________________________________ > 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) > > -- 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, Google Phone and Text -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20180911/09a18fbb/attachment.html> _______________________________________________ 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) |
Free forum by Nabble | Edit this page |