-
Want to remove ads? Register an account and login to see fewer ads, and become a Supporting Member to remove almost all ads.
Amazing Core Tesla Battery IP - 18650 Cell
- Thread starter CapitalistOppressor
- Start date
Dane Dad
Member
I asked a Tesla store rep last week. He said it contains excess coolant for the batteries (or something to that effect). The technology is way out of my league, so I didn't inquire further. Would be great to get a definite opinion on what that box does...?
stopcrazypp
Well-Known Member
Section 0039 in your link mentions fluid coolant.
- - - Updated - - -
That's 2 battery modules stacked on top of each other (there may also be some coolant hoses under there). The other 14 modules are single layered (not stacked).
http://www.teslamotorsclub.com/showthread.php/16535-Battery-facts?p=333846&viewfull=1#post333846
I agree that the cost of the internals is cheap. As far as I can tell they are manufactured at a Fab (or Fabs) in Japan, and then the internals are shipped to China for assembly into a battery. (if anyone knows differently, feel free to speak up)
Panasonic (or any business) does not make production decisions like this lightly. They consider this workflow to be the most economical method the build the batteries. Given that, I can think of two reasons to build the cores in Japan.
First, you better protect your IP from the Chinese. Make no mistake, the Chinese are robbing us blind with focused efforts to swipe IP from western countries. Manufacturing the core in Japan keeps key process IP out of the hands of the Chinese (the chemistry itself is an open book to anyone willing to open a battery up and study it).
Second (and at least as important). Manufacturing the core is almost certainly a relatively cheap, simple and automated process regardless of where you do it. In contrast, assembling the battery requires a large number of tasks, including the mass production of large numbers of tiny components, which must be integrated with the cores and turned into a finished battery. The Chinese specialize in doing task intensive manufacturing for cheaper than anyone else, so it makes sense that Panasonic would want to ship cores to China for final assembly.
In any case, we know that Panasonic thinks that they can make more money shipping cores to China for final assembly before re-shipping finished batteries to the rest of the world. So those assembly costs must be a fairly significant chunk of the total battery cost in order for the process flow to be economical.
Tesla's battery dramatically reduces the number of tasks required. All of the tiny components and parts that are required for the commercial battery have been replaced with an aluminum cap. Those parts MUST be a significant chunk of of the cost, because every part (no matter how tiny) requires a substantial production process, and these dozens of parts lines must flow into the primary production line and get integrated. For Tesla, the workflow is essentially to insert the Panasonic core into a steel tube and then cap it with an aluminum disk/gasket combo.
Yes, the patent I linked was from Tesla's work to productize what was started in prototypes like the ACP cars.
( I was trying to say I don't think ACP used liquid cooling, but "see here" where Tesla patented liquid cooling as an improvement.)
I think the ACP 18650 pack was very crude in comparison to what Tesla engineered.
Tesla put a huge focus on engineering in safety so they could use high density cells that can be unstable if not coddled properly.
stopcrazypp
Well-Known Member
I misunderstood what you were saying then. You are right that ACP didn't use liquid cooling. Even the MINI-E had an air-cooled pack:
http://www.miniusa.com/minie-usa/pdf/MINI-E-spec-sheet.pdf
Cross posted because it relates to this thread -
There is no need for a separate production run. The only difference is the cap, which is manufactured separately, and then integrated into the cell. The cap of a conventional cell is a highly complex device, with several safety systems to prevent the cell from exploding during use. The cap of Tesla's cell is an aluminum disk that has a gasket ultrasonically welded to it.
A Tesla "production run" consists of the worker ultrasonically welding a Tesla cap to the battery at that stage of the production process. This amounts to reaching into a separate bin for the appropriate part.
Here is a video that demonstrates the manufacturing process. I'd suggest watching the whole video to understand how the films are made for the internal guts, but the processes relevant to the cap start around the 3:00 mark. After the necking process, you integrate the cap, but in the video, they are demoing the machines instead of production sequence. You'll see the cap integration maybe a minute later during the spot welder demonstration.
Again, at this point you just reach into a different parts bin. And the Tesla part is vastly cheaper.
Before viewing the video, please look at the relevant patent diagrams. Here is the conventional battery -
Cell cap assembly with recessed terminal and enlarged insulating gasket - diagram, schematic, and image 02
And here is Tesla's battery -
Cell cap assembly with recessed terminal and enlarged insulating gasket - diagram, schematic, and image 01
The cap is a very expensive part of the battery (possibly the single most expensive part), as it takes large numbers of tasks to complete. If you look at the whole video, you will see how the films for the internal guts are just an automated rolling process, and you add chemicals. These cores should be incredibly cheap.
There is no need for a separate production run. The only difference is the cap, which is manufactured separately, and then integrated into the cell. The cap of a conventional cell is a highly complex device, with several safety systems to prevent the cell from exploding during use. The cap of Tesla's cell is an aluminum disk that has a gasket ultrasonically welded to it.
A Tesla "production run" consists of the worker ultrasonically welding a Tesla cap to the battery at that stage of the production process. This amounts to reaching into a separate bin for the appropriate part.
Here is a video that demonstrates the manufacturing process. I'd suggest watching the whole video to understand how the films are made for the internal guts, but the processes relevant to the cap start around the 3:00 mark. After the necking process, you integrate the cap, but in the video, they are demoing the machines instead of production sequence. You'll see the cap integration maybe a minute later during the spot welder demonstration.
Again, at this point you just reach into a different parts bin. And the Tesla part is vastly cheaper.
Before viewing the video, please look at the relevant patent diagrams. Here is the conventional battery -
Cell cap assembly with recessed terminal and enlarged insulating gasket - diagram, schematic, and image 02
And here is Tesla's battery -
Cell cap assembly with recessed terminal and enlarged insulating gasket - diagram, schematic, and image 01
The cap is a very expensive part of the battery (possibly the single most expensive part), as it takes large numbers of tasks to complete. If you look at the whole video, you will see how the films for the internal guts are just an automated rolling process, and you add chemicals. These cores should be incredibly cheap.
Last edited by a moderator:
lolachampcar
Well-Known Member
Thanks. I forgot to mention that the ability to ultrasonically weld the cap, instead of spot welding it as you must do with a conventional cap, means there is no heat. Which means you can immediately insert the core and get on with production, instead of setting it aside to cool.
Also, easier/less dangerous/faster.
PeterW
Member
Elon has stated on more than one occasion that the cell chemistry is different to the standard 18650 cell. I would have thought that would mean a separate production run?
Last edited by a moderator:
It sounds like a separate production run to me. Why don't you think they're having Panasonic or somebody else build the batteries to their (Tesla's) specs including the cap? That would be much more efficient since Panasonic already has most of the equipment and can do it in the same line and production run. I don't think they have "workers reaching in bins" I suspect it's all automated, but don't know for sure. I also doubt if they're ultrasonically welding the gasket to the cap. It's more likely that they're welding the leads and tabs to the cap. The caps are aluminum and ultrasonic welding allows them to use a dissimilar metal for the leads. It's also useful because it doesn't make anything hot so it can be performed while the cap is in close contact with less temperature tolerant materials like the large gasket.
Well, they won't be having Panasonic build the battery because it's cheaper to do it themselves and it protects their IP.
I agree the core+cap would be automated. In case people didn't notice, the video CapO posted said it was for testing: small equipment to make small test battery runs at reasonable cost. I 'm sure battery manufacturers do a large number of test iterations and efficie t small-scale manufacturing would save a lot of money.
It oughta be automated. Whatever process you use though, you will just feed the appropriate caps from a parts bin.
- - - Updated - - -
I've heard him state on more than one occasion that the batteries are a different chemistry from the Roadster, and I've heard him say they are not stock batteries. Do we have a citation of him, or anyone from Tesla saying these are a different chemistry? I'm not against the idea, but I've not seen evidence of it. Regardless, the cores are built in Japan and flown to China for assembly into the battery. So yet again, a production run for Tesla would be just a different parts bin. Though in this case, the part would almost certainly increase costs.
Right. Thanks again for the link. I wish a shareholder would have asked in fhe meeting about the Panasonic relationship. As far as I can reason, Gen 3 success would depends on a $/kWh advantage and would imply so much demand from Tesla cars+grid management/renwable/home and business price arbitrage +licensed car batteries that cell requirements would be a magnitude greater. Had I been there I'd have asked whether they'd had talks with Panasonic to build a US fab.
bollar
Disgruntled Member
Isn't Tesla locked into using Panasonic cells for the next four years / 80K cars, which would preclude them from using other manufactures? Or are you talking about some other construction nuance?
Panasonic Enters into Supply Agreement with Tesla Motors to Supply Automotive-Grade Battery Cells | Press Releases | Tesla Motors
Panasonic Enters into Supply Agreement with Tesla Motors to Supply Automotive-Grade Battery Cells | Press Releases | Tesla Motors
It has nothing to do with protecting their IP. It's way cheaper to have Panasonic do it because they already have factories built to produce batteries. Tesla doesn't, and they are capital constrained. Their IP is already protected whether they contract to have Panasonic build the cells or do it themselves.
How can you be so sure? Having worked a lot in companies with IP, my experience is that you don't just rely on your patents. You rely on not letting others see how you do things, and to ensure that you learn more about the processes than anyone else. When people get practical experience with your IP, they get a much better understanding of both the IP and the subject matter, making it much easier for them to circumvent your patent, challenge it in court, or invent around it.
If you have important IP, you want to keep the related process inhouse as much as you can.
William13
Active Member
Partnering with Panasonic or other battery manufacturer is part of Tesla's strategy. They can switch to other suppliers in the future as battery tech changes without being wedded to a single tech. Li ion batteries are evolving fast enough that Tesla can take a chance on losing some IP and still stay very superior especially as they are patenting multiple ways of making a battery pack.
Similar threads
