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Thread: Panasonic phasing out of Cylindrical Battery Business

  1. #91
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    Default Re: Panasonic phasing out of Cylindrical Battery Business

    Quote Originally Posted by Gauss163 View Post
    But use of Li-ion cells is now ubiquitous due to the popularity of vaping. Moreover the ability to safely use Li-ion cells requires more than just intelligence. It also requires the discipline to religiously follow safety rules. Otherwise the one time you get lazy you may end up like the hobby shop owner who left his pack unattended for 10mins and it burned down his shop.

    Properly designed Li-ion devices help cover our ass when we make the inevitable human error - whether it be from lack of safety knowledge, laziness, etc.
    There's also examples of laptops burning down shops when left unattended and plugged in. I don't rely on safety mechanisms protecting me from problems. I make sure never to charge any lithium-ion device (or loose cells) when I'm not home or when I'm sleeping.

    During charging is really the only time I'm paranoid of lithium-ion batteries. During use, or sitting idle, they shouldn't cause a safety issue unless there's something wrong (like a short). Measure voltage before and after charging, and you should be good to go. Yeah, there is a very rare chance of a cell catching fire for no reason, but there are way more dangerous things in life.

    For lazy people (or newbies), I always recommend Eneloops.

  2. #92

    Default Re: Panasonic phasing out of Cylindrical Battery Business

    While that incident happened 2015. Hopefully by now people have learned that liion is not to be taken lightly. What is interesting enough that not many consumers even know what is a 18650, at least from what i have encountered.

    And the other half of it is knowing where to buy these cells. I do not trust Ebay or even Amazon when it comes to buying liion's. Oh and those ultrafires claiming 9800mAh. How are these allowed to sell?? That should be illegal for false advertisements and putting users at risks.

    How are these sellers in question are able to continue doing business knowingly these cells are a dud.

  3. #93
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    Default Re: Panasonic phasing out of Cylindrical Battery Business

    Quote Originally Posted by WalkIntoTheLight View Post
    There's also examples of laptops burning down shops when left unattended and plugged in.
    Alas, even the best protection circuits can't help much in the case of internal shorts (one of the major causes of such problems). But there are improvements (ceramic separators, heuristic prediction of impending shorts, etc) which have helped minimize such risks compared to early times.

    Quote Originally Posted by WalkIntoTheLight View Post
    I make sure never to charge any lithium-ion device (or loose cells) when I'm not home or when I'm sleeping.
    That's one of the primary safety rules for Li-ion.

  4. #94

    Default Re: Panasonic phasing out of Cylindrical Battery Business

    I think we're getting a bit off track here. Lithium ion safety is and should be a perennial topic, but the focus of this discussion was the current and future availability of Panasonic cylindrical cells.

    Between what we know about Panasonic and what Jon from Liion Wholesale says he has been told, plainly cylindrical cell production continues. It seems reasonable to accept that supply for small quantities of Panasonic cells is tight and should be expected to remain so. And Panasonic is likely to continue to discourage or perhaps even try to more actively prevent 2170 cells from being sold this way.

    One part of the discussion I was curious about was Jon's comment:

    Quote Originally Posted by Jon-LiionWholesale View Post
    Those automotive cells are very unlikely to get out onto the open market and also are unlikely to be suitable for flashlight use for various reasons. Mainly, many of them will be prismatic style, not cylindrical. Even the Tesla 2170 is not something I would ever recommend using outside of a system designed for it. So for the purposes of where flashlights are concerned, they seem to be phasing themselves out of the market.
    Why do you consider the 2170 less suitable for flashlights than the 18650 or 26650 cells already widely in use? Does that opinion apply even to a notional protected 2170 cell?

  5. #95

    Default Re: Panasonic phasing out of Cylindrical Battery Business

    ^^^
    He obviously can speak for himself. But I think the answer or at least part of is in the quote of his that you provided.


    Mainly, many of them will be prismatic style, not cylindrical.

  6. #96
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    Default Re: Panasonic phasing out of Cylindrical Battery Business

    Thank you ~iamlucky13. Yes, please let’s stay on topic. There are other threads for battery safety.

  7. #97

    Default Re: Panasonic phasing out of Cylindrical Battery Business

    Quote Originally Posted by iamlucky13 View Post

    Why do you consider the 2170 less suitable for flashlights than the 18650 or 26650 cells already widely in use? Does that opinion apply even to a notional protected 2170 cell?
    I'll answer this one just to wrap up the discussion.

    I'm specifically talking about the Tesla 2170. Not the 21700 cells being made for non-Tesla use. Other 21700s in general, for example the ones we and others are selling, would be expected to be the same level of risk/safety as the 18650s.

    I'm not very informed about the 2170 specifically since not much information has been released and on this front I don't know any more than anyone else, so this could be an incorrect guess, but in general Tesla has always pushed for a minimum of safety features in their cells, preferring to do external safety protections in the pack instead. Even unprotected cells do have some safety features built in which I expect the Tesla cells are probably missing some or all of them based on their past design decisions.

    Now hopefully we can get back on topic .
    Last edited by Jon-LiionWholesale; 04-26-2018 at 06:32 PM.

  8. #98
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    Default Re: Panasonic phasing out of Cylindrical Battery Business

    I heard that Panasonic most certainly will not be producing 48940 batteries. But it's also likely that they never planned on making 48940's to begin with.... Lol
    Some days you are the bug, some days you are the windshield.

  9. #99
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    Default Re: Panasonic phasing out of Cylindrical Battery Business

    afaik none of the high rate cells have ptc,fuse leads,tearoff tabs,ect.
    if you short them bad things happen quickly.
    protection hinders these type of cell too much.
    thats why tesla uses cell level fuses.
    as to panasonic stopping production of other cylindrical cells the writing has been on the wall a while.
    they are fading fast due to all newer laptops moving to flat lipo.

    Quote Originally Posted by Jon-LiionWholesale View Post
    I'll answer this one just to wrap up the discussion.

    I'm specifically talking about the Tesla 2170. Not the 21700 cells being made for non-Tesla use. Other 21700s in general, for example the ones we and others are selling, would be expected to be the same level of risk/safety as the 18650s.

    I'm not very informed about the 2170 specifically since not much information has been released and on this front I don't know any more than anyone else, so this could be an incorrect guess, but in general Tesla has always pushed for a minimum of safety features in their cells, preferring to do external safety protections in the pack instead. Even unprotected cells do have some safety features built in which I expect the Tesla cells are probably missing some or all of them based on their past design decisions.

    Now hopefully we can get back on topic .

  10. #100
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    Default Re: Panasonic phasing out of Cylindrical Battery Business

    Hello again,

    I had not figured the non cylinder cells into the picture yet. That's worse yet. I am almost sure that my bigger light would need a very big mod to get it to work with the new cells that are not cylindrical. It would need the part of the light that holds the batteries to be enlarged or something and shaped so that it holds the cells properly and makes good contact with the top contact area.
    This would require significant rework of the main body of the light, just not the head.
    Since the body screws on, i would need a lathe that could handle around 2.5 inch diameter pieces, and since i dont have that i would have to find another way like maybe bolt a new body onto the head. Probably tap and thread the head to accept machine screws, like 3 or 4 of them. Maybe then make the bottom come out to replace/charge the cells.

    Deserves much more thought though. Maybe start a thread about this kind of thing, for different kinds of lights?
    Take care,
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  11. #101
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    Default Re: Panasonic phasing out of Cylindrical Battery Business

    ...On its Feb. 5 earnings call, Panasonic said it missed targets for its rechargeable battery division, which includes its automotive batteries for Tesla. “We didn't earn as much as we hoped in areas we considered promising, but we surpassed expectations everywhere else,” Chief Financial Officer Hirokazu Umeda told reporters. Panasonic expects its battery business to lose 5.4B yen in 2018...
    https://www.freightwaves.com/news/20...t-improvements

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    Default Re: Panasonic phasing out of Cylindrical Battery Business

    ...Japan’s Panasonic Corp lifted its outlook for earnings this year [2018] after reporting a 23 percent jump in third-quarter operating profit on healthy sales of car components and factory automation equipment...

    ...Production delays in the Model 3 have led Panasonic to downgrade the full-year forecast for its rechargeable battery business to an operating loss of 5.4 billion yen from a profit of 6.6 billion yen previously, highlighting the impact of any change in strategy at the U.S. electric vehicle maker...

    ...It started mass production of battery cells at Tesla’s Gigafactory in Nevada earlier last year and started mass production at a new plant in Dalian, China in December. It is also adding new production lines in Japan....
    https://www.reuters.com/article/us-p...-idUSKBN1FP0UO

  13. #103

    Default Re: Panasonic phasing out of Cylindrical Battery Business

    Hope Panasonic has a plan B for those extra cells that will soon be overstocked after this

    https://read.bi/2IxRXsD

  14. #104
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    Default Re: Panasonic phasing out of Cylindrical Battery Business

    Quote Originally Posted by iamlucky13 View Post
    2.) Heavy demand in the EV industry especially means some battery types are not easily available other than in industrial quantities.

    3.) Small cylindrical cells are expected to be replaced in many applications in the long term by large prismatic cells. This is not happening yet, but some folks in the distribution chain may be prematurely assuming it's imminent.
    Tesla initially went with 18650 because it was a commodity:
    • Almost every cell manufacturer made 18650
    • Every chemistry was available in 18650
    • Every new advancement in Li-Ion was immediately available in 18650
    • Short of a massive investment in volume production, 18650 lead other formfactors in priceerformance - $/WH, $/peak amp, $/cycle, etc
    • The 18650 format makes for relatively simple thermal management due to its high surface area : volume ratio; the small diameter results in better heat dissipation throughout the cell
    • In a multi-kWH pack, if a handful of 18650 cells degrade or fail the effect on performance will be negligible relative to a pack with fewer, larger cells


    Tesla could follow the major automakers into larger-capacity prismatic packs. But for the reasons above, they still use small cylindrical cells in their packs. Their transition to 20700s doesn't really change this: high-density (3.5AH) 18650s are ~12.5WH while their 20700 cousins (4.8AH) are ~17.25WH. I gather that the other automakers aren't as enamored with cylindrical cells and have opted for large prismatics - perhaps to ensure supply via contractual arrangements with suppliers, perhaps out of habit and their traditional spare parts business, and also perhaps out of packaging concerns: most of the electric cars they've produced in the last <10 years since CA lease-only compliancemobiles have given way to mass-market vehicles sharing a platform with an ICE model, thus their packaging requirements might demand space efficiencies that Tesla's clean sheet designs do not. Boeing's first iteration of 787 batteries highlights some of the inherent problems with large prismatic cells - greater surface area:volume efficiency begets unavoidable thermal resistance that's hard to monitor and can't necessarily be managed under high-draw conditions.

    18650s might fall out of favor with laptop manufacturers who are steadily transitioning to Li-Po, but I expect cylindrical cells to remain popular with power tool manufacturers. They demand a physical robustness that Li-Po can't offer, and even moreso than Tesla are dependent upon standard sizes. It's possible that the availability of standard prismatics with dimensions similar to cylindrical cells such as the 18650 and 21700 might find foothold in applications where volumetric efficiency is a must, but that brings added cell costs, some sacrifice of mechanical robustness, the efficiency bump is small, and such designs would largely negate the minute amount of cooling that cylindricals offer in the gaps between cells in a hexagonal arrangement.
    I apologize that this letter is so long; I did not have time to write a short letter

  15. #105
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    Default Re: Panasonic phasing out of Cylindrical Battery Business

    Quote Originally Posted by idleprocess View Post
    Tesla initially went with 18650 because it was a commodity:
    • Short of a massive investment in volume production, 18650 lead other formfactors in priceerformance - $/WH, $/peak amp, $/cycle, etc
    • [...]

    Tesla could follow the major automakers into larger-capacity prismatic packs. But for the reasons above, they still use small cylindrical cells in their packs. Their transition to 20700s doesn't really change this: high-density (3.5AH) 18650s are ~12.5WH while their 20700 cousins (4.8AH) are ~17.25WH. I gather that the other automakers aren't as enamored with cylindrical cells and have opted for large prismatics - perhaps to ensure supply via contractual arrangements with suppliers, perhaps out of habit and their traditional spare parts business, and also perhaps out of packaging concerns [...]
    That's not quite accurate. 18650's do not lead other form factors in price performance (even restricted to cylindrical format). That's one of the primary reasons why other EV manufacturers have chosen larger prismatics instead - which further offer greater design flexibility, e.g. they don't suffer from an ~100μm limit on electrode thickness in cylindrical cells (any thicker and the electrode coating would crack because they are wound in cylindrical cells vs. stacked in prismatics).

    The transition from 18650s to larger format 20700s does change it, e.g. it lowers their cost/kWh to be much closer to prismatics (e.g. see the final chart below where "Optimistic"=20720 NMC cells are only slightly costlier than prismatics).

    Below are excerpts from a 2017 study that extends the common BatPaC PBCM (process-based cost model) for cell manufacturing costs. The model incorporates all of the steps involved in cell manufacture, e.g.




    Below is a chart summarizing their results. There "BaseLine" = 18650 cell, "Optimistic" = 20720 cell, and "Prismatic" = 25Ah prismatic cell. Notice the large improvements that the 20720 offers - esp. in the higher-rate LMO chemistry on the left. There note that the (per kWh) cost of the 18650 materials alone is almost the same as the entire cost of the prismatic - which highlights the reduction in hardware costs afforded by using larger format prismatic cells.



    Excerpted from: Comparison between cylindrical and prismatic lithium-ion cell costs using a process based cost model, by Rebecca E. Ciez, J.F. Whitacre, Jnl. Power Sources, 340 (2017) 273-281.
    Last edited by Gauss163; 05-11-2018 at 09:40 AM.

  16. #106
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    Default Re: Panasonic phasing out of Cylindrical Battery Business

    Quote Originally Posted by Gauss163 View Post
    That's not quite accurate. 18650's do not lead other form factors in price performance (even restricted to cylindrical format). That's one of the primary reasons why other EV manufacturers have chosen larger prismatics instead - which further offer greater design flexibility, e.g. they don't suffer from an ~100μm limit on electrode thickness in cylindrical cells (any thicker and the electrode coating would crack because they are wound in cylindrical cells vs. stacked in prismatics).
    Perhaps I should have emphasized my point to a greater degree. At the time that Tesla was getting started with the Roadster launch in 2008 and during the run up to the Model S in 2012, 18650 Li-Ion cells were the best choice for the company. Their then highly competitive price : performance ratios along with being an industrial commodity meant that a fledgling startup could make cars using a COTS product using existing supply channels and focus limited financial/engineering resources on more pressing needs.

    Their continued reliance on cylindrical cells may be due to tooling / plant synergies between 18650/20700 footprints, easy transition of pack control electronics/cooling/management, or some other business strategy that negates the performance gap between cylindrical and prismatic cells. The fate of the Model 3 will be telling, however I doubt that a ~5-20% cost delta on the cell cost (pretty sure they're not using high-rate chemistry) will be the primary cause of their demise should the Model 3 fail.
    I apologize that this letter is so long; I did not have time to write a short letter

  17. #107
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    Default Re: Panasonic phasing out of Cylindrical Battery Business

    Quote Originally Posted by idleprocess View Post
    Perhaps I should have emphasized my point to a greater degree. At the time that Tesla was getting started with the Roadster launch in 2008 and during the run up to the Model S in 2012, 18650 Li-Ion cells were the best choice for the company [...]
    Many folks disagree with that, since the same sort of analysis as above shows a great advantage for prismatics.

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    Default Re: Panasonic phasing out of Cylindrical Battery Business

    Quote Originally Posted by Gauss163 View Post
    Many folks disagree with that, since the same sort of analysis as above shows a great advantage for prismatics.
    That is always a interesting analysis, who knows best: The people doing and using the money or the people that sit back and tries to analyze whats happening.

    If the world was based on university people, it would probably never move forward, it needs people doing things, even if xx% of university people says it is a bad idea. Sorry, but we got way to many cases with "educated" people says something that do not match with the practical experience optimal solution. I know that they can show experiments that match exactly with what they say, but they do not explain the limitation of the experiments.

    With the above, do the analysis show that prismatic cells are best with Wh/weight, Wh/volume, Wh/impact, Wh/safety, Wh/power, Wh/??? or only on some of the parameters?

    I believe that cylindrical cells may have an advantage due to mechanical robustness and cooling.
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  19. #109
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    Default Re: Panasonic phasing out of Cylindrical Battery Business

    Quote Originally Posted by Gauss163 View Post
    Many folks disagree with that, since the same sort of analysis as above shows a great advantage for prismatics.
    If you want to dig out figures circa 2003-2008 to demonstrate that Tesla f__ked up, knock yourself out; the 2017 date on your seemingly-paywalled excerpt suggests it's based on analysis a markedly closer to today than when Tesla was planning the Roadster and Model S ~15 years ago. Make sure you look into the commitments that the battery industry likely would have demanded in exchange for a moderately more efficient product and compare that to their early financials.
    I apologize that this letter is so long; I did not have time to write a short letter

  20. #110
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    Default Re: Panasonic phasing out of Cylindrical Battery Business

    Quote Originally Posted by HKJ View Post
    That is always a interesting analysis, who knows best: The people doing and using the money or the people that sit back and tries to analyze whats happening.
    If the world was based on university people [...]
    I don't understand why you are so often skeptical of professional literature. While no doubt there is plenty of academic research on Li-ion tech that never becomes practical, the above is very far from that. Such process-based cost models are widely used in industry for such purposes. If you do a web search on the term you can quickly find links to such applications, e.g. the excerpt below mentions a few.

    PBCM was developed for analyzing the economics of emerging manufacturing processes prior to investment [19] and extended to show the implications of alternative design specifications and process operating conditions on production costs [11]. Today, process-based cost models have been used to assess material, design architecture, and process decisions ranging from composite automobile body production and assembly [20,21] to photonic and electronic semiconductor chip design [22][23][24][25], to printed circuit board and optoelectronic transceiver assembly [24,26,27] and packaging [28,29]. The forecast of a PBCM is based on a detailed simulation of each step of the production process and the interaction across these steps in the full production system. ...
    PBCM is not some pie-in-the-sky research that never made it out of ivory towers. Rather, it is a standard technique widely used in industry. Likely the large cell manufacturers use this (or similar) methods to perform such analyses. The only difference is that they may be able to do slightly more precise analyses since they have access to more precise (cost) data, etc.

    The results of the paper I linked are consistent with other analyses and general industry trends. I see nothing at all controversial in their results so I am baffled why anyone would be so skeptical of these results.
    Last edited by Gauss163; 05-11-2018 at 03:33 PM.

  21. #111
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    Default Re: Panasonic phasing out of Cylindrical Battery Business

    Quote Originally Posted by idleprocess View Post
    If you want to dig out figures circa 2003-2008 to demonstrate that Tesla f__ked up, knock yourself out
    Those were your claims, so that is your responsibility. The decisions made by Tesla way back then may have been motivated by other factors unrelated to pure cost analysis. Musk's logic does not always appear to be rational, and is often questioned by experts.

    The paper was linked through sci-hub, so is freely accessible.
    Last edited by Gauss163; 05-11-2018 at 03:01 PM.

  22. #112
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    Default Re: Panasonic phasing out of Cylindrical Battery Business

    Quote Originally Posted by Gauss163 View Post
    I don't understand why you are so often skeptical of professional literature. While no doubt there is plenty of academic research on Li-ion tech that never becomes practical, the above is very far from that. Such process-based cost models are widely used in industry for such purposes. If you do a web search on the term you can quickly find links to such applications, e.g. the excerpt below mentions a few. .....
    Well if you go back and look at what all the experts had said about Musk's 18650 plans early on, you would hopefully come away with a healthy skepticism of 'experts'. Some of those experts might have even commented on the first cellular phone systems.

  23. #113
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    Default Re: Panasonic phasing out of Cylindrical Battery Business

    Quote Originally Posted by StandardBattery View Post
    Well if you go back and look at what all the experts had said about Musk's 18650 plans early on, you would hopefully come away with a healthy skepticism of 'experts'. Some of those experts might have even commented on the first cellular phone systems.
    I have no idea what that vague remark is supposed to mean. Likely it has little if any relationship to the matters I mentioned above.

  24. #114

    Default Re: Panasonic phasing out of Cylindrical Battery Business

    My thread has certainly turned into an interesting and EGO inflated debate. Who is right, who has to be right and who needs to be right?

    Time will tell if it has not already!

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