Tesla's gigafactory dropping 18650's and going with 20700 - per Elon Musk

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billcoe

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Elon Musk at recent investor conference:
"At the annual shareholder meeting on May 31, Tesla announced that its battery output potential could triple to nearly 105 gigawatt-hours of battery cells and gigawatt hours of battery packs for energy storage. Combined, that is nearly three times the total production of lithium ion batteries in the entire world. Musk also noted that the battery plant will also be updating the form factor of its existing cylindrical Li-ion cell that carries a 18 mm diameter and 65 mm height better known as an 18650 to a larger diameter and taller 20700 cell (20 mm dia x 70 mm height).”

Should be an interesting future we approach.

full link:
http://cleantechnica.com/2016/06/06/5-billion-tesla-gigafactory-worth-50-billion-analyst-estimates/
 

TinderBox (UK)

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A photo`s worth a thousand words (Ugh did i really say that:thinking:)

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John.
 

StorminMatt

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Oh wow! I thought it was going to be 26650 size! I was hoping it would be and that 26650 flashlights would benefit from all the R&D.

That's what I thought, too. I would think that larger cells would reduce cost by decreasing the number of connections and cell compartments, as well as by simplifying battery management.
 

sinner-cpf

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Tbh it doesnot matter what kind of battery size they end up going with since they're making them from scratch, while their strategy is plausible i feel like its the kind of thing one brings up in a stakeholder meeting and press-releases to justify spending and progress.

^John has a valid point, there is empty space that accounts for 10-15% of the volume, these batteries need very less heatsinking (if any at all) if they can get 1.33x capacity this way, they could definitely get another 0.33x by just filling up this empty space.

A typical 18650 (INR) is on average 3000mAh and 20700 should only be 4000mAh.. if you fill the empty space you can bump this up to 5000mAh.. then why not?
 

vadimax

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Latest Tesla fire in Norway (caught fire at charging post, no people were inside when it burst into flames; destroyed completely in minutes):

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Lumencrazy

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Tbh it doesnot matter what kind of battery size they end up going with since they're making them from scratch, while their strategy is plausible i feel like its the kind of thing one brings up in a stakeholder meeting and press-releases to justify spending and progress.

^John has a valid point, there is empty space that accounts for 10-15% of the volume, these batteries need very less heatsinking (if any at all) if they can get 1.33x capacity this way, they could definitely get another 0.33x by just filling up this empty space.

A typical 18650 (INR) is on average 3000mAh and 20700 should only be 4000mAh.. if you fill the empty space you can bump this up to 5000mAh.. then why not?

All of you are just guessing. For example, the Tesla battery packs are liquid cooled. A 10-second search on the internet will bring up a number of articles. Also, batteries are engineered to their final dimensions.There are not determined by some face-saving board meeting prank. Where do you guys get all of this disinformation. This is one big gossip column.
 

SubLGT

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Tesla just hired a new employee:

Tesla Motors [NASDAQ: TSLA] has a new powerhouse in the world of lithium-ion battery research joining the team. Quartz* reports that: "Jeff Dahn, a leading battery researcher who teaches at Dalhousie University in Nova Scotia, will go on an exclusive contract with Tesla Motors on June 8... And Dahn says he is arriving with marching orders to do 'whatever it takes' to improve the company’s battery performance."
According to his bio, "Jeff Dahn is recognized as one of the pioneering developers of the lithium-ion battery... [and] is the author of over 500 refereed journal papers and co-inventor of 58 inventions with patents issued or filed."


https://evannex.com/blogs/news/1179...tever-it-takes-to-improve-battery-performance


http://qz.com/690936/teslas-newest-...ady-to-hear-some-hard-truths-about-batteries/
 

Lynx_Arc

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Sounds a bit like a desperate plan by someone to "improve" the bottom line. If their manufacturing equipment that makes batteries is limited to this new size of battery without major work on it then I guess I can see why they would do this but if they have to make all new equipment to accommodate the larger cell size then why not go to 22800 or even larger? The only savings I can see is they can use less cells to get the same amount of power but the less cells may not take up any less size perhaps even more size when they are grouped together as the holes between cells I believe will be larger and the cells are taller too. I don't think that other battery makers are going to copy this size if they don't get a contract making batteries for them as larger cells will only make laptop and drill battery packs larger as they are built around certain voltages and eliminating batteries to make a taller wider but not necessarily longer pack isn't going to be worth it. Looking at all my 18650 based devices... flashlights and power banks and such I don't see a larger diameter more comfortable a fit.
 

Poppy

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doing the math... pie r squared x length in mm and we get:

18650 = 16,532 mm cubed
20700 = 21,980 mm cubed
26650 = 34,492 mm cubed

therefore using their conjecture, we should be seeing about 2X capacity of 3400 mah 18650s in 26650s, or about 7,000 mah 26650s.

I think the reputable 26650s go up to about 4800 mah.
I think only UltraFire brand makes 7,000 maybe 7,200 mah ones hehehe.
 

MAD777

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Volume ratios do not match performance ratios. It's true that a 26650 is twice the volume of an 18650 battery, but it's energy in watt-hours is only 1.6 times as much.

The industry put all its R&D efforts into the 18650 battery. As a result, all other form factors do not produce the energy per size that the 18650 does.

This is why many of us were hoping for Tesla to go to 26650 as that would presumably result in industry improvements in its efficiency, which would trickle down to flashlights.
 

billcushman

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I watched the whole 3 1/2 hour presentation of the Tesla Stockholders Meeting in which Elon Musk and their CTO JB Straubel described all the details of their history. The 18650 battery they use is not like the 18650 we can buy from Panasonic. It is specialized for their application. The following discussion on the Tesla Forum may be interesting.

https://forums.teslamotors.com/forum/forums/technical-battery-discussion
 
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