18650 Batteries

[stopcrazypp]

So what? That is in no way support his point that NCRxxxxA is the exactly the same cells that TM ordering from Panasonic...

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And I explained why...

My point is you don't have evidence either that they are different. I have pointed at plenty of evidence they are likely the same:
1) the cells are made in the same factory (in Suminoe, Japan, which makes both the NCR18650 and the NCR18650A)
http://www.rutronik.com/news+M5fb8cf031bb.html
2) The first 3.1Ah cell coming out of that factory made was handed in person to Tesla's CTO Straubel
http://www.engadget.com/2010/04/23/panasonics-3-1ah-batteries-to-be-used-in-the-tesla-model-s-hav/
3) The flagship 3.1Ah cell at the time was exactly the NCR18650A
4) they have the exactly same capacity (3.1Ah)
5) they are the same form factor (18650)
6) they both use the NCA chemistry

The only thing I don't have is Tesla or Panasonic explicitly saying that the 3.1Ah cell in question has a model number of NCR18650A (I don't expect them to EVER do that because no other EV manufacturer have ever done that either nor do they have a reason to), but it's very easy to connect the two.

The evidence you have is a PDF that talks examines Panasonic's NCA chemistry vs existing LiCoO2. It's not comparing "consumer" NCA vs "EV optimized" NCA as you are suggesting. It mentions the same chemistry is used in the 140 cell module that Panasonic recently released. That module uses 2.9Ah cells. And at the time of release (10/2009), the only 2.9Ah cell Panasonic was making was the NCR18650.
http://panasonic.co.jp/corp/news/official.data/data.dir/en091001-3/en091001-3.html

The cell tested in the PDF is a "400 mAh cylindrical type".

I would be convinced if you can provide a PDF document that compares different "formulations" of the NCA chemistry with extremely different cycle life under the same conditions.

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But so do my "opponent"!

By the way, in a different thread he just tried to claim exactly the opposite, that automotive 18650 cells are very different from notebook/tablet ones! :wink::biggrin::biggrin:

Real wholesale price of kWh li-ion cells, at the end of 2012/start of 2013.

I did not say the opposite, I said this:

Standard 18650 $/kWh have always been much better than other automotive optimized chemistries and cells.

What I'm referring to is 18650 based on standard Cobalt based chemistries (Tesla being the only one that used it in an automotive application).

There are other chemistries that use the same 18650 form factor:
(LiFePO4, same chemistry as the prismatic cells used in the Karma and Spark)
http://www.a123systems.com/lifepo4-battery-cell.htm
(LiNiMnCo, similar chemistry to GM Volt)
http://www.batteryspace.com/new-gen...50-rechargeable-cell-3.6v-2600mah-9.36wh.aspx

Notice they are completely different chemistries and in the automotive application all of the cells chosen are prismatic (not 18650).

 

[qwk]

Stop is most likely right. The likelyhood of a separate automotive chemistry is very slim.

 

[JRP3]

And to make the point further, Zzzz is claiming same chemistry but "tweaked" I guess, maybe by construction, to provide greater cycle life. Now it is possible to build a more durable cell with the same chemistry, for example by using fewer but thicker layers, but you then also change the other parameters of the cells, specifically the C rates, and possibly energy density. So if there were an "automotive" version of the 3.1ah cell it would have lower C rates, not a good thing, and it might have different capacity. Further evidence that Zzzz is wrong.

 

[Zzzz...]

.

Ok, if you guys want to believe that cells made for an automotive applications are exactly the same as ones made for notebook/tablets(NCR18650A) - then that is your choice.

I think otherwise, but whatever. I have tried to explain as to why such thing would not make economical, technological or market sense. But that part was simply ignored. Moreover, Tesla position always was that Panasonic is a cells supplier with whom relationships happened to be publicized. And Tesla Motors have business relationships with other battery suppliers.

As for "evidences", for example NCR18650 and NCR18650A also made by same company on same factory, share same chemistry(NCA) and same form factor(18850). That do not make them identical cell. So such "evidence" could not possibly serve as proof that cells TM getting from same factory are identical to whatever other cells Panasonic produce there. Plus one could find plenty of examples of cells with same capacity while being actually different cells.

Again, I explained as to why I think automotive cells are different from notebook/tablet ones.

But you guys claim I'm wrong and automotive cell is identical to tablet one(NCR18650A)... Whatever then, I have tried my best to explain as to why such thing make no sense.

 

[Doug_G]

My spider sense is tingling... things are verging on getting personal here.

No one has hard evidence on any of this, so let's agree to disagree and move on.

Thanks

- mod

 

[teddyg]

How would the demise of the 18650 cell affect Tesla?

Hi guys,
Just been talking to some people about the Microsoft Surface and how many now agree that because they added a keyboard and kickstand, they have just made the standard bulky old laptop obsolete. I can see the MS Surface working great for students and business people on the go. Only those needing a lot of computing power will need the bulky old laptop going forward it seems, and that is a very small minority.
You can bet Apple will be copying Microsoft soon and coming out with an iPad keyboard any day now, and then all the other electronics companies will follow suit. It seems the skinny tablet with portable keypad and kickstand format will win the day here.

Not that it will all happen overnight but it seems then that the demand for the larger 18650 cell will be on the decline in the near future. Tesla has relied on the mass production of the 18650 in ever greater numbers to lower costs for the cell and to encourage continued development in its capacity. However I think further investment in 18650 cell development is now less likely to occur because of the shift to these thin tablet like devices.

What would Tesla use if not the 18650? Does anybody know what type of battery is used in the thin Surface/Ipad like devices? Could these thin cell batteries be stacked and joined in series like Tesla is now doing with the 18650? Could Tesla realistically join and monitor 20,000-30,000 of these cells in an EV?

Maybe this could benefit Tesla as they would likely soon be the biggest single customer for the 18650 cell, with a lot of factories geared up to produce it and not much demand, Tesla might be able to request a better price?

On the other hand if companies can't make a profit selling the 18650 cell they may just stop its production altogether. Then what would Tesla do? It seems that the larger cells being used in the Nissan Leaf or Volt are more expensive and not as efficient.

Just thought I would start the discussion on this now because it is likely to come up sooner or later. Tesla should be making plans either way.

What do you guys think?

p.s. Sorry Mods if I posted this in the wrong area, because its not a Model S issue but a Tesla-wide battery issue I was unsure of where to post. Feel free to move to another area if needs be.

Cheers.

 

[Jason S]

Considering that Tesla is having the cells specially made on contract already... no worries.

 

[efusco]

I tend to agree, the volume they're using ought to be enough to keep a line running exclusively for them. But I don't think the traditional laptop is going away anytime soon anyway, maybe a gradual transition, but not overnight and by then Tesla may be ready for some other format anyway.

 

[Grendal]

Tesla is using so many of the batteries Panasonic would section off a piece of whatever factory where they are made just for Tesla.

It's in Panasonic's interest to design the best battery possible - period. Packaging is irrelevant.

On the crazy chance that it actually is discontinued worldwide then Tesla would just have to redesign their battery pack for the new common battery packaging.

 

[Zzzz...]

Worldwide yearly production rate of all cells currently stands at around 4.6 billion units. That is all li-ion cells, including 18650 ones. But most of those cells go into cheap cell phones and such...

This year most likely Tesla produce around 30 000 cars. Assuming 7 000 cells per car Tesla demand would translate to 4.57% of all worldwide market of li-ion cells produced. Not sure how many of all cells are 18650 ones, but I would gustimate that Tesla already on a track to consume over 10% of worldwide production of 18650 in 2013.

Fast forward few years forward - when TM hit 100k-200k production rate, do the math.

Tesla is in position to order/design any form factor they would think is a best one. With this scale of the orders price of producing different form factors would be negligible from price of 18650...

 

[dsm363]

Tesla has said before that their design isn't tied to one particular supplier (although they have the Panasonic contract mentioned above) or a particular battery shape. They would have to likely redesign the pack of course for a different sized cell but that should be relatively easy for them given enough lead time.

 

[richkae]

The surface is a good looking product, and I might get one, but it does not make laptops obsolete.
I actually frequently use a laptop on my lap, and the surface can't do that.
The keyboard - while better than a tablet - is not good enough for heavy use.
The Surface ( Pro ) has limited battery life.
The energy consumption of CPUs does not go down as they get more powerful. Even if the rest of the components get slimmer, a big battery is still needed.

I don't doubt that the tablet ( and surface ) form factor are biting into laptop sales, but I'm not worried about them going obsolete until someone comes up with a new input technology `surpassing the keyboard.
If a surface, tablet and laptop are within reach - I will pick my laptop unless I am just going to read or browse.

 

[ElSupreme]

Hi guys,
Just been talking to some people about the Microsoft Surface and how many now agree that because they added a keyboard and kickstand, they have just made the standard bulky old laptop obsolete.

When I looked up the cost of the Surface Pro I was so disappointed, then I looked at the specs and realized it was a full fledged laptop (in a new form factor). I think that this will be the future of the laptop computer, at least for consumers. But ...

The Surface ( Pro ) has limited battery life.
The energy consumption of CPUs does not go down as they get more powerful. Even if the rest of the components get slimmer, a big battery is still needed.

I think MS or whoever will get a nice thin quality keyboard worked out. But the battery in the Surface Pro is about 1/4 of what it should be. I agree that battery power is all that remains to be solved to make a full computer tablet possible.

I think that 18650 wont go anywhere for a while. Plus I doubt that businesses will drop the standard laptop any time soon. And there is still the slow steady trickle of desktops being converted to laptops. I still have my desktop and will have one as long as they keep making parts.

 

[richkae]

I think MS or whoever will get a nice thin quality keyboard worked out.

No matter what they do a thin floppy thing still won't work on a lap. You need a rigid platform and I prefer keys that depress.

 

[ElSupreme]

No matter what they do a thin floppy thing still won't work on a lap. You need a rigid platform and I prefer keys that depress.

Did you try their 'real' keyboard. They make two for the surface. One was a travel quality keyborad, was rigid and had buttons. I agree that the fabric weird touch based keyboard won't cut it.

 

[Renderdog]

I was surprised Tesla uses standard batteries, I can imagine 7000 cases adds weight and complexity, though I don't know much about Li-ion battery technology. I'm sure they had good reasons to go with standard batteries at first, but maybe they'll transition to larger cells in the future?

 

[Zextraterrestrial]

You can replace AA's w/ 18650's and use 1/3 or 1/2 as many batteries (for some things).

I think the 'gel' packs are not as durable as the cans and different chemistry but there are other threads about that
I think the form factor should stay around for a while.

 

[ElSupreme]

I was surprised Tesla uses standard batteries, I can imagine 7000 cases adds weight and complexity, though I don't know much about Li-ion battery technology. I'm sure they had good reasons to go with standard batteries at first, but maybe they'll transition to larger cells in the future?

They use the 18650 form factor. But they chemistry is specially for Tesla (or so they say) and is automotive grade. I am sure the 7000+ cases add weight but they also add a bunch of safety, and ease of packaging. The LEAF and Volt have to have compression fitments for their pouch cells, to prevent swelling. Tesla just has to protect them from external sources.

I have a feeling that the 18650 cells are also much easier to have machines assemble the battery packs, and weld on contacts, versus trying to clamp in a bunch of pouches.

 

[vfx]

Hand power tools must have a large portion of the market. All those brands using the same 18650 in their packs.

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I was surprised Tesla uses standard batteries, I can imagine 7000 cases adds weight and complexity, though I don't know much about Li-ion battery technology. I'm sure they had good reasons to go with standard batteries at first, but maybe they'll transition to larger cells in the future?

Same as with the Roadster. A commodity cell is cheaper and the design work is done. Tesla put all their patents and energy in the battery box packaging and the electronics that maintain the batteries. As stated above, once they went from 6831 cells in the original 2,500 Roadsters on the road, to 8,000 cells in the 20,000 cars per year in the Model S, they were able to ask for an automotive grade version from the supplier (s).

 

[MitchL]

I was surprised Tesla uses standard batteries, I can imagine 7000 cases adds weight and complexity, though I don't know much about Li-ion battery technology. I'm sure they had good reasons to go with standard batteries at first, but maybe they'll transition to larger cells in the future?

Actually, I think the 7000 cells is Tesla's secret sauce.

- By using commodity form factors, they get the benefits of commodity pricing. Even if they use their own special chemistry, they get to use Panasonic's already-built production lines.
- The pack's architecture and series/parallel geometry, using thousands of small cells, ensures that single cell failures don't take out the whole pack.
- Lots of cells provide many options for wear balancing, temperature control
- The geometry is part of how you can do supercharging -- each cell is individually limited on charge rate, but if you can charge many small batches in parallel, you can recharge the whole pack faster than with a smaller number of large cells.

They may choose to use larger cells someday, but it'll be when they're buying enough cells to be able to specify everything, then they can design the "perfect" cell size to fit within their design.

(I'm far from an expert, but I do think the pack architecture is what sets Tesla apart from its competitors).

/Mitch.