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



## billcoe (Jun 8, 2016)

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/


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## vadimax (Jun 8, 2016)

Funny. They are going to produce batteries that are useless to us.


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## MAD777 (Jun 8, 2016)

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.


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## TinderBox (UK) (Jun 8, 2016)

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







John.


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## StorminMatt (Jun 8, 2016)

MAD777 said:


> 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.


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## TinderBox (UK) (Jun 8, 2016)

Why are they going for cylindrical cells, would hexagonal cells pack more in the same space, or do they need a slight gap for cooling?






John.


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## sinner-cpf (Jun 8, 2016)

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?


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## SG Hall (Jun 8, 2016)

vadimax said:


> Funny. They are going to produce batteries that are useless to us.



Anyone else see the day soon when the first 20700 light gets designed? Probably 5 years time when the patent expires. 🤔


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## vadimax (Jun 8, 2016)

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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## vadimax (Jun 8, 2016)

Some Tesla hacking:


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## Lumencrazy (Jun 8, 2016)

sinner-cpf said:


> 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.


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## m4a1usr (Jun 8, 2016)

vadimax said:


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



Ouch! Now that's having a bad day.


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## SubLGT (Jun 8, 2016)

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/


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## davidt1 (Jun 8, 2016)

Love the picture above. Looks like a scene out of a Batman movie.


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## Lynx_Arc (Jun 8, 2016)

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.


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## Poppy (Jun 8, 2016)

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.


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## MAD777 (Jun 8, 2016)

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.


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## billcushman (Jun 8, 2016)

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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## TinderBox (UK) (Jun 8, 2016)

I have seen a used Tesla battery pack on eBay for a couple of thousand dollars.

Also i have seen those small nuclear battery`s that use a decking isotope to produce power.

John.


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## MAD777 (Jun 8, 2016)

TinderBox (UK) said:


> Also i have seen those small nuclear battery`s that use a decking isotope to produce power.
> 
> John.


Oh please don't tell Vinh that there are nuclear batteries! LOL
[emoji33]


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## billcushman (Jun 8, 2016)

This is an interesting discussion about the Tesla Battery. 

https://www.youtube.com/watch?v=VbVpPSa6glA


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## TinderBox (UK) (Jun 8, 2016)

Great video, over 7000 18650 cells in the car power pack, But will we CPF ever see the improvements in battery capacity that Tesla make or will it be a guarded secret, now they are making their own 20700 cells in the US.

John.



billcushman said:


> This is an interesting discussion about the Tesla Battery.
> 
> https://www.youtube.com/watch?v=VbVpPSa6glA


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## SubLGT (Jun 8, 2016)

Lynx_Arc said:


> ...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.



I can see the 20700 size working well in battery packs for yard equipment, such as mowers, string trimmers, hedge trimmers, etc.


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## stephenk (Jun 9, 2016)

Given the rate at which flashaholics buy new lights and cells, then even if the 20700s reach the flashlight market and 20700 flashlights start to be produced, it is probably not a major issue?


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## CuriousOne (Jun 9, 2016)

20700 are available from chinese manufacturers for quite a long time.


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## CuriousOne (Jun 9, 2016)

One example:

http://www.ydlxny.com/en/product_d1.asp?idd=57&ids=4&SortID=18&id=18&idid=4&ord=6


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## stephenk (Jun 9, 2016)

So we'll be seeing a 13,333mAh Ultrafire 20700 then?


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## sidecross (Jun 9, 2016)

Thank you for those who provided excellent links on battery technology. :thumbsup:


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## Gauss163 (Jun 9, 2016)

The ~10% increase to the 18650 size is not unique to Tesla, e.g. last year Samsung SDI announced a 4750mAh 21700 cell (vs. Telsa 20700) targeting the e-bike market, see below


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## etc (Jun 9, 2016)

I wonder if 20700 becomes the new standard if this really takes off.


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## Gauss163 (Jun 9, 2016)

Here is the tentative datasheet for Panasonic's 4250mAh NCR20700B. Below are the first 2 pages.


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## SemiMan (Jun 9, 2016)

TinderBox (UK) said:


> Why are they going for cylindrical cells, would hexagonal cells pack more in the same space, or do they need a slight gap for cooling?
> 
> 
> 
> ...



It's rolled layers of film. They are naturally cylinders.


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## SemiMan (Jun 9, 2016)

Lynx_Arc said:


> 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.



Most of the dollars in laptop batteries is not 18650 any more.


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## etc (Jun 9, 2016)

If they are not 18650 anymore, what are they?


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## TinderBox (UK) (Jun 9, 2016)

Most likely li-polymer as they can be made to fit virtually any shape, though they are normally in ultrabooks with built-in battery`s i would think 18650 are still used in the removable battery notebooks.

John.



etc said:


> If they are not 18650 anymore, what are they?


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## SemiMan (Jun 9, 2016)

The dollars are not in removable batteries any more. 

To be successful these days, laptops have to be at least somewhat thin. 

Take a perusal of Lenovo or Dell's website. You are hard pressed to find removable batteries any more or anything powered with 18650. They are just too thick.

Pretty much all lithium polymer. It's the same chemistry, just different physical construction.


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## ChrisGarrett (Jun 10, 2016)

Like somebody said above, power tools are the new laptops for cylindrical cells, IMO.

It used to be draws drills, saws and lights that used battery packs, but now we have blowers, weed whackers, hedgers and even lawn mowers.

None of the tree-hugger hippies want gas any longer and 100 yard extension cords are too much work for the fatties, to roll up.

Chris


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## derek10 (Jun 10, 2016)

I read that cylindrical cells last longer than prisms and pouch cells.


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## derek10 (Jun 10, 2016)

ChrisGarrett said:


> Like somebody said above, power tools are the new laptops for cylindrical cells, IMO.
> 
> It used to be draws drills, saws and lights that used battery packs, but now we have blowers, weed whackers, hedgers and even lawn mowers.
> 
> ...



Also many powerbanks. Mine all have Samsung 18650 cells


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## sidecross (Jun 10, 2016)

SemiMan said:


> The dollars are not in removable batteries any more.
> 
> To be successful these days, laptops have to be at least somewhat thin.
> 
> ...


I replaced my 5 year old laptop with a new Dell XPS13 9350 and it is 2.5 lbs and 10mm thick with battery life of eight hours. An 18650 battery would not fit.


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## StorminMatt (Jun 10, 2016)

Lynx_Arc said:


> 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.



When it comes to hexagonal packing of cylinders, the void ratio is independent of the diameter. It is always .0931. So there is neither a gain nor a loss here. On the other hand, the battery casing itself can take up a lower percentage of the total real estate on a larger cell, allowing more of the cell to be active material. This can increase the energy density if larger cells are used.


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## JB007Rules (Jun 10, 2016)

SemiMan said:


> Most of the dollars in laptop batteries is not 18650 any more.



Maybe for the consumer market this is true since they are all thin and light... This isn't true AT ALL for the commercial and military market though.... I'm a managing partner at one of the largest Toughbook re-sellers in the country (Rugged Depot) and coming from 12+ years in the Panasonic Toughbook world, Panasonic OWNS the rugged laptop market and they are mostly 18650's but they are slowly going towards either 14500's or something similar to make the laptops skinnier.

Seeing as ALL the cells are Panasonic (They invented the 18650) it's an IN for them to sell their laptops with their cells in them too 

I'd be interested to see what Panasonic can offer for these consumer grade laptops as you said they don't have 18650's in them. They are probably losing the business to Samsung or LG on those cells

Thanks!


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## Gauss163 (Jun 10, 2016)

StorminMatt said:


> When it comes to hexagonal packing of cylinders, the void ratio is independent of the diameter. It is always .0931



But that packing density is for packings in the _infinite_ plane. For packings into some finite region you also need to account for the voids left at the _boundaries _of the region, which smaller cells will generally fill better. For example, see this page on circle packings in a square.


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## CuriousOne (Jun 11, 2016)

Modern laptops mostly use 16650 cells. UR16650ZT generally.


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## PH1 (Jun 11, 2016)

Lynx_Arc said:


> 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.


Some power tool manufactures has already switched from 18650 cells to 20700 cells.
So Telsa isn't inventing a new cell format for the Giga Factory / Model 3. They just use the 20700 cell format that's already sold by power tool manufactures.

Metabo 18V LiHD packs use 20700 cells, they were introduced to the market already a year ago in May 2015. 
Metabo LiHD: https://www.metabo.com/com/en/info/news/highlights/lihd-battery-pack-technology/
Metabo LiHD battery pack capacities:
Slim pack (5s1p): 3100 mAh
Fat pack (5s2p): 5500 mAh and 6200 mAh.
Accroding to http://www.werkzeug-news.de/Forum/v...&sid=f9a4c70cc4bbc14e0a40d9ec6280a742#p324039 Metabo LiHD is based on Panasonic/Sanyo NCR20700A cells.

Bosch is also coming out with an EneRacer GBA 18V 6.3 Ah fat pack battery based on 20700 cells this fall.
Press release - Bosch Power Tools relies on connectivity:
http://www.bosch-presse.de/presseforum/details.htm?txtID=7664&tk_id=112&locale=en


> The latest example of innovative cordless technology from Bosch is the high-performance battery GBA 18V 6,3 Ah EneRacer Professional, which will be available from autumn 2016. An improved power connector within the cells ensures lower internal resistance, which means that higher currents can be drawn from the cells over a longer time. The result is an increase in available power in a compact battery.


It also looks like Bosch has switched to from nickel to copper connections between the cells to lower the internal resistance of the battery pack.

Pictures of the new Bosch 6.3 Ah EnerPower battery pack and 20700 cells:
Picture sources:
Pic 1-6: https://www.bosch-professional.com/de/de/community/category/eneracer-die-neue-akkutechnologie/10603405-t
Pic 7-9: http://www.sg-toolbox.com/bosch-eneracer/


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## Kurt_Woloch (Jun 11, 2016)

As far as I know, self-balancing boards still use 18650 batteries. And currently their sales vastly outnumber sales of electric cars with millions of boards having been shipped to the USA so far. ;-)


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## JB007Rules (Jun 11, 2016)

Speaking of power tools.

I have taken apart almost all of my DeWalt packs (I have a quite an extensive collection  ) the larger 20V's have 10 high drain 18650's in them (pancake/smaller ones only have 5 of course) (5.0AH's have the blue 2500MAh's in them and the 3.0's have 1.5MAh's in them and they are red in colr)

5 * 3.7V nominal = 18.5V... 4V*5 = 20V "MAX"... They are 18V batteries but in the US they are marketed as 20V... the EXACT same batteries in Europe are 18V!  ( http://toolguyd.com/blog/wp-content/uploads/2012/07/Dewalt-18V-XR-4-0Ah-Battery-Gauge.jpg ) - Since they can't get away with stretching the truth there... 

The 8V gyro screwdriver has TWO 14500's . The 12V ones have 3 x 18650's in them.






Thanks!


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## snakebite (Jun 11, 2016)

etc said:


> If they are not 18650 anymore, what are they?



lipoly pouch cells.
apple has been using them a long time.
most high end slim notebooks now use them.


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## Kurt_Woloch (Jun 11, 2016)

Well, I have seen laptop batteries having a unusually high voltage... Dell laptops, specifically. I think those are 3S batteries, but they charge up to about 13.12 V (which is 4.37 V per cell), having a nominal voltage of 12 volts (4 volts per cell). However, the voltage doesn't seem THAT high to me... it's maybe 0.2 V per cell higher than the voltage of the cells Lenovo uses in T60/T61 batteries.


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## Gauss163 (Jun 11, 2016)

Kurt_Woloch said:


> Well, I have seen laptop batteries having a unusually high voltage... Dell laptops, specifically. I think those are 3S batteries, but they charge up to about 13.12 V (which is 4.37 V per cell)...



Those are cells that charge to 4.35 volts, and they have been in use for many years in laptops.


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## parametrek (Jun 11, 2016)

Lumencrazy said:


> the Tesla battery packs are liquid cooled.



This also put an upper limit on the size of cell Tesla can use. Smaller cells are easier to cool than larger cells since they have more surface area for a given amount of watt-hours. But as battery technology improves they can use larger cells. Specifically a lower internal resistance means less heat generated inside the battery.

Regarding the research that has gone into 18650 cells, all of that directly carries over to any size cell. Every li-ion cell is basically rolls of metalic foil and moist paper in a vented metal tube. But 18650 cells get the latest and greatest manufacturing processes before other sizes because that is where the demand is.


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## PH1 (Jun 12, 2016)

JB007Rules said:


> Speaking of power tools.
> 
> I have taken apart almost all of my DeWalt packs (I have a quite an extensive collection  ) the larger 20V's have 10 high drain 18650's in them (pancake/smaller ones only have 5 of course) (5.0AH's have the blue 2500MAh's in them and the 3.0's have 1.5MAh's in them and they are red in colr)
> 
> ...


Yes it a well known fact that power and garden tool manufacturers lie about the voltage, especially in North America, by stating a made up marketing/max voltage of 4 V per li-ion cell instead of the nominal 3.6 V per cell. To convert from Vmax to Vnominal, simply multiply Vmax by 0.9.

4 Vmax = 3.6 Vnominal
8 Vmax = 7.2 Vnominal
12 Vmax = 10.8 Vnominal
16 Vmax = 14.4 Vnominal
20 Vmax = 18 Vnominal
24 Vmax = 21.6 Vnominal
28 Vmax = 25.2 Vnominal
...
40 Vmax = 36 Vnominal
56 Vmax = 50.4 Vnominal [EGO garden tools for example use 50.4 Vnominal batteries but market them as 56 V].
... and so forth.

Actually all li-ion cells used in power and garden tools has a nominal voltage of 3.6 V, not the 3.7 V used in you calculations, you can confirm this by looking of the nominal voltage of these cells in the datasheets. The cells used in power tools are has a very low internal resistance / very high max. continuous discharge rate and all these cells only has a nominal voltage of 3.6 V.
Lower discharge rate li-ion cells like the ones use in laptops has a nominal voltage between 3.7 and 3.8 V and can store more energy [Wh], partly due to the higher nominal voltage, as energy storage is calculated as nominal voltage [V] * capacity [Ah]. 
You can't have both very high max. continuous discharge rate and the highest capacity in the same type of cell. That's why you should never use laptop cells for power tools as they can't handle the high current draws and has too high internal resistance. Laptop cells are instead designed to have the highest possible energy storage.
You can however use power tool cells in laptops, but they will have lower capacity.
Some of thee most common cells used in power tools by several brands are the Samsung SDI INR18650 cells listed here: http://www.samsungsdi.com/lithium-ion-battery/power-devices/power-tool.html
As you can see they all have a nominal voltage of 3.6 V, but very high max. continuous discharge rate.
Their Samsung ICR18650 laptop cells on the other hand has nominal voltages up to 3.78: http://www.samsungsdi.com/lithium-ion-battery/it-devices/laptop.html


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## JB007Rules (Jun 12, 2016)

Thank you for clarifying the 3.6 VS 3.7 on the voltage. I think I know where I went wrong on this. See below:

I have also taken apart my mini-dyson battery pack as it shows 22.2V on the casing.... it has 6 x 18650's inside of it (Of course right lol).

3.7*6 = 22.2...

In closing I think that TOOL manufacturers in SPECIFIC use 3.6V and other companies (Such as Dyson in this case) use 3.7V.

Not sure on why that it as Panny says that it IS certainly measured as 3.6 nominal per their datasheet.

Thanks!


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## Gauss163 (Jun 12, 2016)

PH1 said:


> ...Yes it a well known fact that power and garden tool manufacturers lie about the voltage, especially in North America, by stating a made up marketing/max voltage of 4 V per li-ion cell instead of the nominal 3.6 V per cell....



That would be "lying" only if they used such voltage "labels" to falsely deduce inflated energy ratings (Wh). But I doubt that is true. To compare packs you should compare the _energy _(Wh) they deliver under typical load conditions


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## Lynx_Arc (Jun 12, 2016)

Gauss163 said:


> That would be "lying" only if they used such voltage "labels" to falsely deduce inflated energy ratings (Wh). But I doubt that is true. To compare packs you should compare the _energy _(Wh) they deliver under typical load conditions



That and Alkaline batteries are labeled at 1.5v and rarely have more than 1.55v in them while nimh charged fully are rated at 1.2v and if you measure them it is only under a load or depleted that they measure that low off the charger it is more like 1.4v. A 20v pack would measure 20v with no load on it and perhaps under 18v under a very heavy load even. Off the charger an 18v pack would measure about 4.2v x 5 or 21v. I think battery makers just chose 20v so as to differentiate them from the 18v nicad packs out there which also measure about 20v off the charger I think.

Simply speaking what is the selling point is more the Ahr ratings on packs of similar range with 3Ah 4Ah 5Ah etc. If a 20700 battery were sold as cheap as a similar 18650 battery with the additional mah extra due to physical cell size difference I think it would be a selling point indeed but if you are going to pay more per Ah for 20700 batteries then they won't make a huge splash right away but for those who really are willing to pay considerably extra for the extra capacity they offer. What I wonder is why they don't make large diameter very short cells like a 60200 which could have 2.5 the capacity of a 20700 but I guess that would make it harder to put them in packs with that size of a battery.


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## IamMatt (Jun 12, 2016)

Tesla is just trying to catch up with Mercedes' new battery technology.


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## CuriousOne (Jun 14, 2016)

Earlier DeWalt lithium batteries, which are compatible with older instruments, use A123s LiFePO4 18650 cells.


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## KeepingItLight (Jun 14, 2016)

IamMatt said:


> Tesla is just trying to catch up with Mercedes' new battery technology.




ROTFLMAO!


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## Overclocker (Jun 14, 2016)

larger format is good. saves me from having to weld so many of them


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## MAD777 (Jun 14, 2016)

IamMatt said:


> Tesla is just trying to catch up with Mercedes' new battery technology.



That saleswoman almost sold me a Mercedes! 😄😄😄


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## marinemaster (Jun 18, 2016)

Well now we will never be able to bore Surefire at 20mm diameter....jk
Interesting stuff, before you know it the xyz lithium battery will be the new D battery [emoji2]


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## space-cowboy (Jun 21, 2016)

It will be very interesting to see discharge tests of another new Panasonic batt NCR20650A 30 Amp rated. Notice this "650"


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## SemiMan (Jun 21, 2016)

JB007Rules said:


> Maybe for the consumer market this is true since they are all thin and light... This isn't true AT ALL for the commercial and military market though.... I'm a managing partner at one of the largest Toughbook re-sellers in the country (Rugged Depot) and coming from 12+ years in the Panasonic Toughbook world, Panasonic OWNS the rugged laptop market and they are mostly 18650's but they are slowly going towards either 14500's or something similar to make the laptops skinnier.
> 
> Seeing as ALL the cells are Panasonic (They invented the 18650) it's an IN for them to sell their laptops with their cells in them too
> 
> ...



If by commercial market you mean business, that is not at all true. Corporate laptops have also moved away from 18650 and other easily replaceable sells. 

The rugged market still uses them, but that's but a small portion of the overall market.


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## SemiMan (Jun 21, 2016)

Kurt_Woloch said:


> As far as I know, self-balancing boards still use 18650 batteries. And currently their sales vastly outnumber sales of electric cars with millions of boards having been shipped to the USA so far. ;-)



TESLA alone will consume 100's of millions of 18650 cells this year.


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## JB007Rules (Jun 23, 2016)

SemiMan said:


> If by commercial market you mean business, that is not at all true. Corporate laptops have also moved away from 18650 and other easily replaceable sells.
> 
> The rugged market still uses them, but that's but a small portion of the overall market.



You are correct. I should have been more specific 

Thanks!


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## kreisl (Jul 7, 2016)

Am looking forward to testing the new Tesla round cells. But there is also new e-car battery technology made in gemani going into licensed mass production

http://www.spiegel.de/auto/aktuell/...ic-elektrisiert-mit-neuem-akku-a-1097291.html


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## etc (Jul 15, 2016)

this is what I don't get. There is a certain number of cubic feet or inches or meters that a vehicle has for batteries. No matter what size you make the cell, the overall volume remains the same. Whether you get 4 of these or 5 of the old type, the W-hr will remain the same. 

Common sense suggests that the smaller the cell is, the more of them you will fit in the same volume. Kind of like sand can occupy the entire glass jar and large rocks half the space, with small rocks 5/8 of the space.


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## TinderBox (UK) (Jul 16, 2016)

The bigger the cell the less connections you need, and Tesla puts cooling pipes between the cells, maybe cylindrical cells are not as inefficient as we think.

John


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## Overclocker (Jul 16, 2016)

etc said:


> this is what I don't get. There is a certain number of cubic feet or inches or meters that a vehicle has for batteries. No matter what size you make the cell, the overall volume remains the same. Whether you get 4 of these or 5 of the old type, the W-hr will remain the same.
> 
> Common sense suggests that the smaller the cell is, the more of them you will fit in the same volume. Kind of like sand can occupy the entire glass jar and large rocks half the space, with small rocks 5/8 of the space.




nope. the empty "wasted" space between cylindrical cells is the same for any cell diameter. i.e. if you're gonna pack the maximum amount of cells in a given volume, the empty spaces between cells is the same with bigger cells and smaller cells

but with smaller cells you get more overhead in interconnection, packaging, insulation between cells, etc

and there's also a limit to how big you can go because a big cell would trap heat inside

and since there are space contraints because they're building the cells into the floors of the vehicles i suppose they chose 20700 to be optimal given all the other considerations


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## Str8stroke (Jul 16, 2016)

I have seen and got to sit in the Tesla at their store in Houston. Pretty amazing tech. Personally, I just could not see spending that kinda money on a car that I can't go off road, tow a boat or camper with. That is just me. 

Has any ever done a cost of real world ownership analysis on one? Checking eBay a 2013 is listed around $52K. How long do battery packs last? Cost of installing a home charger station? Cost of electricity to charge vehicle? Other required services? Can a local shop do any services? Stuff I just wonder. Not counting costs, I guess I see the possibility for a big city car, but not so much a car for a young family who may travel.


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## etc (Jul 17, 2016)

Overclocker said:


> nope. the empty "wasted" space between cylindrical cells is the same for any cell diameter. i.e. if you're gonna pack the maximum amount of cells in a given volume, the empty spaces between cells is the same with bigger cells and smaller cells



This is directly contrary to laws of physics and basic geometry. Do you have any proof, or is this just conjecture? 

I am not convinced until you come up with the exact rating for each cell, the number of cells in say 1 cubic meter and so on.

Here is proof via a diagram. Imagine you have one big cell in a cube, there is a lot of wasted space in the first box. 4 smaller cells waste less space and 16 smaller less still and so on, ad infinitum. The more you shrink it, the less space is wasted. A bigger cell has a higher Watt-hour rating but not enough to make up for the tons of space it wastes.

I am not going to take time to draw a precise diagram but this gives an idea. The smaller the cell shrinks the less wasted space is generated. If you could shrink each cell to the size of grain of sand, they would almost completely occupy any given space. They wouldn't be efficient in terms of wiring and stuff. So the idea to get a 20mm cell versus 18mm is just an attempt to reduce costs of wiring and complexity, perhaps fewer failures, but it's not an attempt to increase the Watt-hours of the entire battery. At best, they will end up where they are now with less wiring.


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## etc (Jul 17, 2016)

Str8stroke said:


> I have seen and got to sit in the Tesla at their store in Houston. Pretty amazing tech. Personally, I just could not see spending that kinda money on a car that I can't go off road, tow a boat or camper with. That is just me.
> 
> Has any ever done a cost of real world ownership analysis on one? Checking eBay a 2013 is listed around $52K. How long do battery packs last? Cost of installing a home charger station? Cost of electricity to charge vehicle? Other required services? Can a local shop do any services? Stuff I just wonder. Not counting costs, I guess I see the possibility for a big city car, but not so much a car for a young family who may travel.



The environmental impact is the same as a gas car... because the hidden cost is you still have to charge it and use electricity and thus either coal or nuclear or something. It's just a hidden cost, plus the cost of recycling the battery.


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## Gauss163 (Jul 17, 2016)

etc said:


> Overclocker said:
> 
> 
> > nope. the empty "wasted" space between cylindrical cells is the same for any cell diameter. i.e. if you're gonna pack the maximum amount of cells in a given volume, the empty spaces between cells is the same with bigger cells and smaller cells ...
> ...



Correct. This claim was already refuted last month in this thread. Packings in a finite region (vs. infinite plane) do depend on the sizes, e.g. you get 100% density if you pack a circle into a circle of the same size, but less than that if you pack it with smaller diameter circles. Follow the link for citations.


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## Overclocker (Jul 18, 2016)

same 

you could put 16 little circles in there and the total area would be the same. for some reason this isn't immediately obvious


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## vadimax (Jul 18, 2016)

Exactly. Ratio of a circle area to a touching square area is a constant value (π/4) no matter the size they are. Now we know who was kicking butts at school instead of studying 

There is another issue: generated heat is a function of volume, but dissipated heat is a function of surface area. That is the larger the battery the more it is prone to overheating. More of that, we have no idea about the ability of Li-Ion layers to transfer heat in lateral direction (from layer to layer). So, theoretically, a large battery may be relatively cold outside, but melting in its core.


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## vadimax (Jul 18, 2016)

etc said:


> The environmental impact is the same as a gas car... because the hidden cost is you still have to charge it and use electricity and thus either coal or nuclear or something. It's just a hidden cost, plus the cost of recycling the battery.



Singapore transport authority has calculated 222 g/km of CO2 emissions for Tesla S P85.

I like Singapore


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## Str8stroke (Jul 18, 2016)

vadimax said:


> Singapore transport authority has calculated 222 g/km of CO2 emissions for Tesla S P85.
> 
> I like Singapore


Wow, interesting y'all.


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## Lynx_Arc (Jul 18, 2016)

Overclocker said:


> same
> 
> you could put 16 little circles in there and the total area would be the same. for some reason this isn't immediately obvious


They sometimes use hexagonal packing which is supposed to be more efficient but if one thinks of it as a percentage thing then the size of a circle shouldn't matter if the pattern layout doesn't change to more accommodate the area it is set in you could think of it as looking at the same pattern through binoculars or zooming out to make the "appearance" look bigger or smaller but the wasted space doesn't change via size.


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## Overclocker (Jul 18, 2016)

Gauss163 said:


> But that packing density is for packings in the _infinite_ plane. For packings into some finite region you also need to account for the voids left at the _boundaries _of the region, which smaller cells will generally fill better. For example, see this page on circle packings in a square.









from: http://powercartel.com/2015/03/used-tesla-444-cell-6s74p-modules-for-sale/

the packs are big  you really shouldn't be worrying about the little voids in the ends. a smart designer could utilize that space anyway...


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## etc (Jul 18, 2016)

vadimax said:


> Exactly. Ratio of a circle area to a touching square area is a constant value (π/4) no matter the size they are. Now we know who was kicking butts at school instead of studying
> 
> There is another issue: generated heat is a function of volume, but dissipated heat is a function of surface area. That is the larger the battery the more it is prone to overheating. More of that, we have no idea about the ability of Li-Ion layers to transfer heat in lateral direction (from layer to layer). So, theoretically, a large battery may be relatively cold outside, but melting in its core.




So there it is, the surface area decreases relative to the volume with overheating being a real problem.


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## etc (Jul 18, 2016)

Gauss163 said:


> Correct. This claim was already refuted last month in this thread. Packings in a finite region (vs. infinite plane) do depend on the sizes, e.g. you get 100% density if you pack a circle into a circle of the same size, but less than that if you pack it with smaller diameter circles. Follow the link for citations.




I do not see a refutation anywhere. I see this link which just proves the point. The latest item at the end reads 0.248 which is the highest value except for 0.250 at the top but would be interesting to see the next value. 

https://en.wikipedia.org/wiki/Circle_packing_in_a_square


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## Gauss163 (Jul 21, 2016)

Overclocker said:


> same
> 
> you could put 16 little circles in there and the total area would be the same. for some reason this isn't immediately obvious



But such tiling only works for certain regular shapes, e.g. it is not true for packing circles into circles. In any case it is a moot point since thermal constraints usually prevent use of optimal packing density configurations.


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## Lynx_Arc (Jul 21, 2016)

Gauss163 said:


> But such tiling only works for certain regular shapes, e.g. it is not true for packing circles into circles. In any case it is a moot point since thermal constraints usually prevent use of optimal packing density configurations.



You can look up packing circles and if you get a large enough amount of circles then making them smaller or larger shouldn't affect the loss of size if you pack them the most efficient way which isn't this way but rather hexagonally (6 around 1) It is said this is 91% efficient and larger or smaller the 91% efficiency doesn't change if the size of the space to fill doesn't add loss around the outer edges by too large of circles I would think. It is akin to zooming in and out on perhaps 100 cells packed like this and you can perceive smaller or larger circles but the percentage of wasted space only changes on the outer edges where there isn't space enough to add a new cell but more space than normal loss between cells.


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## Gauss163 (Jul 21, 2016)

Lynx_Arc said:


> You can look up packing circles and if you get a large enough amount of circles then making them smaller or larger shouldn't affect the loss of size if you pack them the most efficient way which isn't this way but rather hexagonally (6 around 1) It is said this is 91% efficient and larger or smaller the 91% efficiency doesn't change if the size of the space to fill doesn't add loss around the outer edges by too large of circles I would think. It is akin to zooming in and out on perhaps 100 cells packed like this and you can perceive smaller or larger circles but the percentage of wasted space only changes on the outer edges where there isn't space enough to add a new cell but more space than normal loss between cells.



Not true. Look at any reference on circle packing in circles, e.g. this Wikipedia page. With 2 circles you get 50% density, 3 = 65%, 4,5 = 69%, 6 = 67%, 7 = 78%, 8 = 73%, 9,10 = 69%, etc, not reaching 80% till 19 circles.


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## Lynx_Arc (Jul 21, 2016)

Gauss163 said:


> Not true. Look at any reference on circle packing in circles, e.g. this Wikipedia page. With 2 circles you get 50% density, 3 = 65%, 4,5 = 69%, 6 = 67%, 7 = 78%, 8 = 73%, 9,10 = 69%, etc, not reaching 80% till 19 circles.



Try this page
https://en.wikipedia.org/wiki/Packing_problems


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## Gauss163 (Jul 21, 2016)

Lynx_Arc said:


> Try this page
> https://en.wikipedia.org/wiki/Packing_problems



What's your point? That's the parent of the page I pointed you at and it contains only 1 sentence on packing circles in circle (a link to the page I gave - which refutes your claims).


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## Overclocker (Jul 22, 2016)

someone's being a square peg in a round hole. or specifically, trying to pack circles in circles when they should be packing them into rectangles


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## Lynx_Arc (Jul 22, 2016)

Gauss163 said:


> What's your point? That's the parent of the page I pointed you at and it contains only 1 sentence on packing circles in circle (a link to the page I gave - which refutes your claims).



The point is when it comes down to the usage of packing batteries related to this thread they are using far more than 19 batteries to begin with which pretty much makes arguments based upon that irrelevant. With hexagonal packing there becomes a point where you have to make the circles way too big in order to negate it as the most efficient method used.


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## Gauss163 (Jul 22, 2016)

Lynx_Arc said:


> The point is when it comes down to the usage of packing batteries related to this thread they are using far more than 19 batteries to begin with which pretty much makes arguments based upon that irrelevant...



It seems we both agree that the theoretical results have limited value in practice, and those results have now been linked for those who have interest in such, so I don't see any value in continuing down this tangent.


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## Lynx_Arc (Jul 22, 2016)

Gauss163 said:


> It seems we both agree that the theoretical results have limited value in practice, and those results have now been linked for those who have interest in such, so I don't see any value in continuing down this tangent.


Well it was an interesting (and enlightening) exchange nevertheless. I think the one issue on cell size that is perhaps important is the height difference as we can agree the diameter (in these large packs) isn't going to have much of an affect on power of the battery but rather the 2mm increase in height or about 11% and this will translate into that much more power if the energy to volume ratio of 20700s match 18650s which I believe they will be about the same. I think it all depends on how you stack the batteries in the end if they vertical then unless the pile is 10 high (for 18650s) then changes in height would happen but at 10 cells high that would equal 9 high of the 20mm cells so you essentially save the expense of 1 less layer of batteries in your pack now how much this equates to cost of the pack isn't known (labor + parts) and how much the 20700s per cell cost would be. If these battery packs cost lets toss a number of $8k at it and equate 11% cost reduction (1 layer) that would make the cost 7120 for a pack with the same amount of power our perhaps 880 dollars a car cheaper to produce and replacement battery costs would be passed onto customers (at least some of the savings). As for % cost of the car itself.. that much on most of these electric cars (Tesla) is minimal but if they start to make $20k electric cars or somehow even $15k electric cars then the difference in price becomes more apparent. 

If they started making devices (lights, etc) that use the 20700 size that wouldn't bother me as there would be a market for sleeves and spacers to use 18650s in those devices so you wouldn't have a lot of useless batteries around. I think if the major 18650 market takes a nosedive because of these competing batteries (20700) that instead of having major battery makers producing multiple capacities/amps of cells we could see offerings diminish down to limited varieties of them and cost go up after they change over and sell of their excess inventory. The uses of 18650 for the sake of most here are devices that IMO don't have a great incentive to be loyal to the battery size once another size takes front stage so power banks and flashlights and stuff they will just start making new ones that take 20700s if that is the prominent type.


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## PH1 (Jul 23, 2016)

kreisl said:


> Am looking forward to testing the new Tesla round cells. But there is also new e-car battery technology made in gemani going into licensed mass production
> 
> http://www.spiegel.de/auto/aktuell/...ic-elektrisiert-mit-neuem-akku-a-1097291.html


By "made in gemani" I guess you meant "made in Germany", but Kreisel Electric is actually "made in Austria".
They are not making a new battery cell technology, but just a new patented liquid (electrically nonconductive) based thermal management technology for battery packs. They don't make their own battery cells, but just pack conventional off-the-shelf 18650 li-ion battery cells into their own battery packs with their own battery management system and their own own patented thermal management technology that keeps a constant cell temperaure ~ 25 °C. All their battery packs are cable of being quick charged 0-80% in 18 minutes and 0-100% in 28 minutes.
They are buling a battery factory which is supposed to be finished in March 2017. But it is only planned to build batteries for 8000 vehicles annually with up to 70 employees, but the capacity can easily be doubled or quadrupled according to the article. But that's still not numbers that will change much and and the article doesn't say that they are going into licensed mass production, but just says that they are don't want to go into mass production themselves, so if any car manufacturer is interested in that they have to license the technology and start their own mass production.

http://www.kreiselelectric.com/en/technology/battery-system/battery-pack/



> *ACTIVE THERMAL MANAGEMENT*
> 
> Kreisel Electric battery cells feature a patented casing that is constantly flushed with liquid. This means that combined with a heat pump, the battery can be heated or cooled very efficiently. This significantly increases range and service life as a result.
> 
> ...


​


----------



## Overclocker (Jul 23, 2016)

https://endless-sphere.com/forums/viewtopic.php?f=14&t=82090


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## kreisl (Jul 23, 2016)

I am not sure why the cell is labeled Sanyo. The NCR20700A and NCR20700B are sold under Panasonic label, geman dealer has it and also sells flashlights:

http://akkuplus.de/PANASONIC-Industrial-Europe-GmbH


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## etc (Jul 23, 2016)

actually it would be cool to get 20mm li-ion cell for my surefires / malkoffs, drastically increasing runtime. I would need aftermarket bodies (FiveMega, here I come)


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## SubLGT (Jul 23, 2016)

kreisl said:


> I am not sure why the cell is labeled Sanyo. The NCR20700A and NCR20700B are sold under Panasonic label...



The 20700B looks interesting, for flashlight use:

rated capacity: 4000mAh
typical capacity: 4250mAh
discharge: 8A

http://akkuplus.de/Panasonic-NCR-20700B-36-Volt-4250mAh-Li-Ion-LiNiCoALO2


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## PH1 (Jul 23, 2016)

kreisl said:


> I am not sure why the cell is labeled Sanyo. The NCR20700A and NCR20700B are sold under Panasonic label, geman dealer has it and also sells flashlights:
> 
> http://akkuplus.de/PANASONIC-Industrial-Europe-GmbH


The NCR18650B cells are sold under both the Panasonic and Sanyo brands, so I guess it will be no different with their NCR20700 cells, since Panasonic owns Sanyo.
Under the Panasonic brand they are green with a large top and under the Sanyo brand they are red.


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## CelticCross74 (Jul 24, 2016)

So Musk is going to build his own factory for producing these cells? Cannot help but feel a sense of foreboding here. I am now finally seeing plenty of Teslas on the roads here around D.C. man they are nice. They are incredibly fast to boot.

I wonder what is inside my Ryobi 40 volt battery packs for my 40 volt yard tools? They do nothing but kick rear end and easily meet gas power without the hassle of gas. My 40 volt trimmer edger I have had for over 4 years and have beat the hell out of it yet it still charges and goes. It finally started to lose capacity noticed so I bought the expensive 5 amp hour 40 volt Ryobi pack and MAN!! It is like I gave my 40 volt Ryobi tools a huge boost of steroids. I wonder what is inside it?


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## Lynx_Arc (Jul 24, 2016)

CelticCross74 said:


> So Musk is going to build his own factory for producing these cells? Cannot help but feel a sense of foreboding here. I am now finally seeing plenty of Teslas on the roads here around D.C. man they are nice. They are incredibly fast to boot.
> 
> I wonder what is inside my Ryobi 40 volt battery packs for my 40 volt yard tools? They do nothing but kick rear end and easily meet gas power without the hassle of gas. My 40 volt trimmer edger I have had for over 4 years and have beat the hell out of it yet it still charges and goes. It finally started to lose capacity noticed so I bought the expensive 5 amp hour 40 volt Ryobi pack and MAN!! It is like I gave my 40 volt Ryobi tools a huge boost of steroids. I wonder what is inside it?


Most tool packs have 18650s in them the 18/20v ones have sets of 5 or layers of them 1 layer for the thin packs 2 layers for the thicker ones if they are 5 Ahr then they have 2500mah 18650s x 2 sets. Yard tools have 10 batteries in series for 40v and if they are big enough possibly 2 sets or 20 batteries. I'm almost sure your 5A 40v Ryobi packs are 2x10 2500mah 18650 batteries (20 pcs).


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## fyrstormer (Jul 24, 2016)

I had no idea they were using cylindrical cells in the first place. They're probably more crash-worthy than flat LiPo cells are, because the metal casing is hard to puncture and a fire is unlikely to spread.


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## Lumencrazy (Jul 24, 2016)

fyrstormer said:


> I had no idea they were using cylindrical cells in the first place. They're probably more crash-worthy than flat LiPo cells are, because the metal casing is hard to puncture and a fire is unlikely to spread.


Many reasons why they use cylindrical cells. One reason it that they hold a higher pressure and do not swell like LIPO cells.


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## fyrstormer (Jul 24, 2016)

Well yes, that's based on the same structural integrity that makes them more crash-worthy too.


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## Lynx_Arc (Jul 25, 2016)

fyrstormer said:


> Well yes, that's based on the same structural integrity that makes them more crash-worthy too.


If one thinks about it you see more cylinders in the market than squares in all sorts of products like beverages, canned food, etc and the reason for this is two fold in that you don't have to try and align machinery to deal with squares and also deal with corners of them in production plus devices that use them if they were all squares making flashlights to use square cells would get more expensive as you probably couldn't turn them on a lathe easily. If you think about it you don't hardly see any square batteries in many chemistries out there in the single cell variety only batteries that have several cells in them are square these days (like 9v, and 6v lantern batteries) and even these have round cell inside of them. I would like to see prismatic cells cheaper than cylindrical ones and see a common size/shape of them such that people will start making products to use them across the board as the prismatic cells are way too many sizes and shapes and I think even times the ones that are supposed to be the same size/shape..... aren't exactly. It may be possible that a breakthrough in batteries comes with one that doesn't have to be concerned about the chemicals wanting to leak in use and also when used up and/or aging a lot and if this breakthrough happens then we could even see flexible "bag" type batteries that you can make fit into a similar volume/size holding container.


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## ChrisGarrett (Jul 27, 2016)

Here's a recent article about a 'tour' of the new Gigafactory.

http://www.bbc.com/news/technology-36893104

"We had just had a tour of the new Gigafactory, Tesla's $5bn (£3.8bn) 3,200-acre battery-manufacturing plant that has already begun production but will not be in full swing until about 2020.

At that point, it will have the largest physical footprint of any building in the world.

By making battery cells here, Mr Musk hopes he will be able to innovate faster and cut out about 30% of the cost.

The factory is a tie-up with the company that already makes Tesla's cells, Panasonic."

Chris


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## FroggyTaco (Jul 27, 2016)

ChrisGarrett said:


> Like somebody said above, power tools are the new laptops for cylindrical cells, IMO.
> 
> It used to be draws drills, saws and lights that used battery packs, but now we have blowers, weed whackers, hedgers and even lawn mowers.
> 
> ...



Or perhaps people have power yard tool needs beyond a 100' cords reach and/or don't want to deal with having to spend 1/2 your time managing the cord & just want to go use the tool like a gas version but even easier since there's no starter cord to pull(how many times?), no choke to manipulate & time to let the engine warm to have a stable idle, no hot exhaust to have to worry about brushing against & getting burned or perhaps starting a fire, no gas to have to tote around & refill & potentially spill, no gas to have to mix with 2 stroke oil & hope you use it up before it goes bad...etc.

Both sets of power(Gas & Battery) have their place in the world. I personally have overall a small & highly infrequent "yard" power tool needs & being able to quickly, conveniently use battery yard power tools & not have to mess with oil changes, gas, 2 stroke mix, gummed up carbs from lack of use, etc has been refreshing. I tried it this year & was astonished at how well they worked relative to the power source.


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## FroggyTaco (Jul 27, 2016)

etc said:


> The environmental impact is the same as a gas car... because the hidden cost is you still have to charge it and use electricity and thus either coal or nuclear or something. It's just a hidden cost, plus the cost of recycling the battery.



Depends on the region. Areas with hydro, geothermal, solar, or wind turbine electrical production have far lower over emission "costs" overall. Also as more higher efficiency & lower emission natural gas plants come online will help as well.


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## FroggyTaco (Jul 27, 2016)

vadimax said:


> Exactly. Ratio of a circle area to a touching square area is a constant value (π/4) no matter the size they are. Now we know who was kicking butts at school instead of studying
> 
> There is another issue: generated heat is a function of volume, but dissipated heat is a function of surface area. That is the larger the battery the more it is prone to overheating. More of that, we have no idea about the ability of Li-Ion layers to transfer heat in lateral direction (from layer to layer). So, theoretically, a large battery may be relatively cold outside, but melting in its core.



How does the larger capacity & therefore likely lower C discharge rate of the larger cell affect heat build-up? I would think that would offset that concern. Of course there will be less overall 20700 cells than 18650 cells so there will be a higher wattage draw per cell but I'm guessing the capacity increase will outweigh the increased current.


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## Connor (Jul 28, 2016)

Seems it's not going to be 20700 cells after all: 
http://fortune.com/2016/07/27/tesla-bigger-battery-gigafactory/

The king is dead, long live the 21-70. :bow:


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## Lynx_Arc (Jul 28, 2016)

Connor said:


> Seems it's not going to be 20700 cells after all:
> http://fortune.com/2016/07/27/tesla-bigger-battery-gigafactory/
> 
> The king is dead, long live the 21-70. :bow:


If this is true then you could replace 7 layers of 18650s with 6 layers of 21700 batteries and be about the same height.


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## SubLGT (Jul 28, 2016)

Interesting comments from Tesla about their battery choice:

http://cleantechnica.com/2016/07/27/10-key-takeaways-tesla-gigafactory-opening/

JB: “We’ve spent a lot of time on this actually. It’s kind of interesting. There are a bunch of tradeoffs. There are some things that get better when you make the cell size bigger, and some things that get worse. 18650 was sort of an accident of history. That was what was standardized for early products. So we revisited all of those tradeoffs and came to this size, which is quite a bit bigger. If you have them next to each other, the actual volume of materials inside is substantially more. And overall it’s about cost optimization.”

Elon: “It really comes from the first principles of physics and economics. That’s the way we try to analyze everything. To say like if no cell existed in the world, what size should it be? What is the size that would achieve the product characteristics we’re looking for, but would be fundamentally optimal? 18650 is not optimal.”


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## SubLGT (Jul 28, 2016)

From 20700 to 21700? Samsung will be happy to hear this.

"...Samsung SDI also unveiled a battery pack product equipped with 21700-type batteries, noted for their upgraded energy capacity compared to previous cylindrical types. The 18650 battery, or rather the small cylindrical battery of 18mm diameter and 65mm length, has been in dominant use until recently. However, the creation of new battery applications has boosted the demand for high capacity batteries. In response, Samsung SDI has come up with a battery that has upgraded a maximum of 35% of energy volume, now known as the 21700 battery, and has successfully applied it onto e-bikes for the first in the world.
The 21700 model can have various applications other than e-bike, such as in electric tools, laptops, and more. It is expected to become the new standard in small cylindrical battery usage…"

http://www.greencarcongress.com/2015...6-samsung.html


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## sidecross (Jul 28, 2016)

Tesla's Battery

http://www.bbc.com/news/technology-36893104


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## FroggyTaco (Jul 28, 2016)

I'm all for the best engineered size cell rather than the "what we have been using for a long time so it's a standard" cell.

So many "standards" throughout our lives are based on archaic & now obsolete/irrelevant platforms that for w/e reason aren't brushed away in favor of the new.

This will also have a positive trickle down effect on all sorts of battery powered high drain devices & create the opportunity for new battery powered devices to come to fruition.


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## SubLGT (Jul 28, 2016)

http://electrek.co/2016/07/28/tesla...and-tidbits-this-is-the-coolest-factory-ever/

Excerpt:

"...When it was my turn, I asked the status of the “20700” battery that has been reported to be going into Model 3…….



They actually changed the size to 21mm diameter and a 70mm height. They also got rid of the trailing ‘0’ so the name of the battery that will be going into the Model 3 is the ’21-70′ 
JB Straubel says Tesla developed this battery this size by starting without preconceived notions. They then optimized for efficiency, size and output. The 18650 standard was called an accident of history though it had served Tesla and others well. Tesla says it predicts that this new 21-70 battery size will become a new standard.
The half centimeter height increase for the car packs would be offset with more efficient battery packaging which will make the packs actually the same thickness or less than current packs and obviously with a higher energy density….."


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## Drift Monkey (Jul 29, 2016)

SubLGT said:


> http://electrek.co/2016/07/28/tesla...and-tidbits-this-is-the-coolest-factory-ever/
> 
> Excerpt:
> 
> ...



Your precious 20770 is DEAD!


----------



## Anders (Jul 29, 2016)

Double post.


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## Anders (Jul 29, 2016)

- Christina Lampe-Önnerud at Cadenza Innovation-"”Elon Musk and I are actually of the same opinion when it comes to small units. But while his idea was to take laptop batteries, put them together in a trough and add the safety on the outside, we’ve placed everything within an aluminum container.”"

http://nordic.businessinsider.com/t...an-increase-the-range-of-teslas-by-70-2016-7/


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## etc (Jul 29, 2016)

I cannot wait to put one in 6P with an aftermarket body. The body will be as big as the head.


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## PH1 (Jul 29, 2016)

Gauss163 said:


> The ~10% increase to the 18650 size is not unique to Tesla, e.g. last year Samsung SDI announced a 4750mAh 21700 cell (vs. Telsa 20700) targeting the e-bike market, see below



According from the latest press conference because of Tesla/Panasonic's grand opening of the Gigafactory today, they are going to use 21700 cells instead of 20700 cells like they previously said.
I don't hope we will be seeing two new standards, both 20700 and 21700. Maybe it's just a matter of how they round off the numbers and they are all around 20.5 mm in diameter. Or maybe 20 mm is just the diameter without plastic shrink tube and 21 mm is the diameter with plastic shrink tube.

http://insideevs.com/highlights-tes...nference-featuring-musk-straubel-panasonic-vp
*Highlights From Tesla Gigafactory Press Conference Featuring Musk, Straubel, Panasonic VP*

*Battery Format*
Straubel:


Tesla CTO J.B. Straubel said:


> _“We’ve spent a lot of time on this actually. It’s kind of interesting. There are a bunch of trade offs. There are some things that get better when you make the cell size bigger, and some things that get worse. 18-650 was sort of an accident of history. That was what was standardized for early products. So we revisited all of those trade offs and came to this size (21-70), which is quite a bit bigger. If you have them next to each other, the actual volume of materials inside is substantially more. And overall it’s about cost optimization.”_


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## FroggyTaco (Jul 29, 2016)

PH1 said:


> According from the latest press conference because of Tesla/Panasonics grand opening of the Gigafactory today, they are going to use 21700 cells instead of 20700 cells like they have already said.
> I don't hope we will be seeing two new standards, both 20700 and 21700. Maybe it's just a matter of how they round off the numbers and they are all around 21.5 mm in diameter. Or maybe 20 mm is just the diameter without plastic shrink tube and 21 mm is the diameter with plastic shrink tube.



Or maybe the 20700 was a smokescreen to through off industrial espionage or enable better negotiations for some contract/deal/terms. Or maybe further testing & tech has came about recently that it's now feasible to employ the 21700 vs the 20700 design. Also perhaps the highly unanticipated demand gave them the freedom to commit more R&D money that helped make the change.


----------



## SubLGT (Jul 29, 2016)

SubLGT said:


> The 20700B looks interesting, for flashlight use:
> 
> rated capacity: 4000mAh
> typical capacity: 4250mAh
> ...



The Samsung 21700 also looks good for flashlight use:

4750 mAh
9A max discharge


----------



## stephenk (Jul 30, 2016)

I would think that 21700 flashlights would be more ergonomic (i.e. fits better in the hand) than 18650s? Sounds like a positive step forward!


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## Drift Monkey (Jul 30, 2016)

The funny part is that 18650s _still _have a better size to energy density ratio. The move to this new size must be purely to save money.


----------



## Lynx_Arc (Jul 30, 2016)

Drift Monkey said:


> The funny part is that 18650s _still _have a better size to energy density ratio. The move to this new size must be purely to save money.


Not necessarily. Higher capacity 18650 batteries tend to have less current potential. It is a trade off of capacity for amperage output. I'm betting that they will get the 21700s at about the same energy density of 18650s with higher current capability in the end... if they are spending billions making a huge factory I'm sure they are pouring a bunch of money into getting every bit of power possible out of these batteries at currents that they need to drive large electric motors. Will the new battery packs have more power than a same sized 18650 based pack? I doubt it will exceed that, but also it wouldn't surprise me if they just matched the same output or maybe 5% less with higher amperage capability which could actually work out to be more power under load than the 18650s do. 
What the magic tradeoff between higher capacity and higher amperage is I really don't know and how many series/parallel sets of these batteries are wired together and hooked up 18650 vs 21700 I don't know either. 

As for 21700s in flashlights I have mixed emotions as AAA "tubes" are too small for constant use IMO, AA is nearly big enough diameter for my hands while 18650 lights are just about right. I guess I've gotten used to smaller diameter lights growing up with most flashlights using D cells I liked the C cell lights they were lighter and more comfortable. I think 21700s will not find themselves into front battery headlamps much the extra weight and size (45%? more) is just too much IMO. 
If companies making other battery packs switch to the 21700s enough we could see the 18650 batteries becoming no longer mainstream as 1 layer of 21700s should be close to 50% more power in tool packs allowing a 1 layer pack to be midway between 1 and 2 layer 18650 packs. I think what will be the main driving force is the cost/power ratio of both cells if the 21700s get the cost/power ratio down below 18650 batteries then it will start to erode the use of them in everything that is based primarily on cost/power and size is less of an issue.


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## Drift Monkey (Jul 30, 2016)

Lynx_Arc said:


> Not necessarily. Higher capacity 18650 batteries tend to have less current potential. It is a trade off of capacity for amperage output. I'm betting that they will get the 21700s at about the same energy density of 18650s with higher current capability in the end... if they are spending billions making a huge factory I'm sure they are pouring a bunch of money into getting every bit of power possible out of these batteries at currents that they need to drive large electric motors. Will the new battery packs have more power than a same sized 18650 based pack? I doubt it will exceed that, but also it wouldn't surprise me if they just matched the same output or maybe 5% less with higher amperage capability which could actually work out to be more power under load than the 18650s do.



So using your theoretical reasoning, why not improve upon existing 26650 cells?

In fact, they did release the specs of the 20700 B cells and they _didn't_ match the current GA cells...it only got to 92% of the energy density (4250 mah) with similar current discharge rates. The 20700 A cells give a mere 300 mah advantage @20A than existing 18650s. 21-70 moves even further away from the ideal.

Unless a battery chemistry breakthrough occurs, this cell format is about cutting costs, plain and simple.


----------



## FroggyTaco (Jul 30, 2016)

Drift Monkey said:


> So using your theoretical reasoning, why not improve upon existing 26650 cells?



Per Elon Musk they decided to design a cell in the present as if there was no other existing format that would suit there needs. Apparently 21700 has the ideal capacity/discharge/charge/packaging specifications an electric car needs.

I would surmise a higher capacity 21700 cell would have less desirable discharge & lifecycle characteristics even if it would work amazing for us flashaholics.


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## Lynx_Arc (Jul 30, 2016)

Drift Monkey said:


> So using your theoretical reasoning, why not improve upon existing 26650 cells?


Because the market isn't there for them... yet. If they decided to use them in electric cars I would assume that they would push the envelope of that size battery to the max just like they have done in the past with 18650s.


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## Drift Monkey (Jul 30, 2016)

FroggyTaco said:


> Per Elon Musk they decided to design a cell in the present as if there was no other existing format that would suit there needs. Apparently 21700 has the ideal capacity/discharge/charge/packaging specifications an electric car needs.
> 
> I would surmise a higher capacity 21700 cell would have less desirable discharge & lifecycle characteristics even if it would work amazing for us flashaholics.





Lynx_Arc said:


> Because the market isn't there for them... yet. If they decided to use them in electric cars I would assume that they would push the envelope of that size battery to the max just like they have done in the past with 18650s.



It's for cost reasons...as stated above. Froggy is on point...it will work "better" for electric cars and be cheaper, this is the real reason.


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## Lynx_Arc (Jul 30, 2016)

Drift Monkey said:


> It's for cost reasons...as stated above. Froggy is on point...it will work "better" for electric cars and be cheaper, this is the real reason.


I'm guessing that there could be a "need" for a minimum amount of batteries in sets (series) in order to get the desired voltage and if batteries get too large in diameter it could be more difficult to wire them together.


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## Drift Monkey (Jul 31, 2016)

New info - the new 2170 cells will have all new state-of-the-art hardware and new battery chemistry! It may even be able to match/beat 18650s in energy density ratio!


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## Burgess (Jul 31, 2016)

Very interesting thread here !


Thank you to everyone, for
your comments and contributions.


lovecpf
_


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## Lynx_Arc (Aug 1, 2016)

Drift Monkey said:


> New info - the new 2170 cells will have all new state-of-the-art hardware and new battery chemistry! It may even be able to match/beat 18650s in energy density ratio!


And if there is improvements to the chemistry and design they could also be incorporated into 18650 cells likewise such that the main difference is again related to size/volume. 

My concern is that other makers of things will be attracted to the new size batteries due to the lower cost/energy ration in devices. If you can get a 2000mah battery for your drill for $75, a 5000mah for $150, or a 3500mah battery for $85 which would you choose? More and more the market on lithium ion powered stuff is about Ampere hours and these batteries IMO could in the future rule the market till someone with a ton of money decides to support an even larger battery size in volume. 

Can this factory that will make these 21700s be retooled cheaply to make 25900s or larger at a later time? We could see more interest in 26650s in the future even. I think cylindrical cells will rule the market in the energy/cost ratio for some time until a completely new chemistry comes available that can favor a different cell design. 

Will they ever get lithium batteries cheap enough to replace car batteries in use and improve them to a point that they can outlast them in hard use in all climates? I'm looking back at the days car batteries cost 1/3 of what they do now and they were competing well with nicads and even nimh prior to LSD nimh.


----------



## kreisl (Aug 3, 2016)

This youtube clip belongs to this thread, gigafactory opening speech yada


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## bob_ninja (Aug 5, 2016)

Lynx_Arc said:


> Not necessarily. Higher capacity 18650 batteries tend to have less current potential. It is a trade off of capacity for amperage output. I'm betting that they will get the 21700s at about the same energy density of 18650s with higher current capability in the end... if they are spending billions making a huge factory I'm sure they are pouring a bunch of money into getting every bit of power possible out of these batteries at currents that they need to drive large electric motors......



Ditto

Friend was telling me about new Tesla X model. When he told me about the motor I didn't believe it and had to check it.
2 motors for combined power about 500 kW   
Sure pack is big 90 kWh but these motors .... OMG
So you are talking about 6C peak power!!!!!

I am guessing the major factor was in fact high current.
I don't know what is the voltage used so blatant guessing game:

500V @ 500 kW = 1,000 A
500 V / 3.7 = 136 cells per module

90,000 Wh / (3.7 V * 5 Ah * 136) = 36 modules

1,000 A / 36 modules = 28 A/module

So 5 Ah cell has to be able to supply peak 28A current!!!!

(sorry my math is likely not accurate, kinda fudging it)


----------



## Lynx_Arc (Aug 5, 2016)

bob_ninja said:


> Ditto
> 
> Friend was telling me about new Tesla X model. When he told me about the motor I didn't believe it and had to check it.
> 2 motors for combined power about 500 kW
> ...



I'm not sure about all these specs but I did a quick check and people were talking about 300 or 375v on the motors themselves and they use an inverter so the battery voltage may be lower or higher than that you basically have to go by watt hours, calculate the number of batteries total and go from there. 

I looked up the information about how many 18650 batteries in a Tesla's 85Kwh pack is claimed to have 16 modules of 444 cells or 7104 cells and a test claims 11.36Wh per battery or about 3.07Ah. Now 444 cells times 3.7v = 1642v nominally or 1864v at 4.2v. 
If we take 500kw divide that by 7104 we get 70W and further divide that by 3.7v gives you 18.9A this is for 18650 batteries in the current packs. I suspect the energy density of 21700s will at least equal 18650 batteries and the number of batteries will drop while the current will rise. 
The big question is how many batteries will fit in the new "Pack" size of 21700s. I suspect it will be a little larger in at least one dimension and it is possible that the "module" size will change too.


----------



## alternety (Aug 6, 2016)

An overall point that seems to be rather under appreciated: Elon probably does not care even a little bit about how the batteries work in flashlights or anything else. The following has been mentioned in this thread, but here is some of it in one place. For those who want to read one post.

His factory can be fully engaged if he sells the number of cars he is projecting. The factory is for cars. Rather like the A123 thing worked out. They were useful to a niche.

RE format: Cylindrical cells provide a relative easy cooling system. Prismatics would seem to be harder to cool in terms of the required cooling channels, surface contact, and interaction with adjacent cells (Think Boeing). Hexagonal, as has been mentioned is not a practical format. Battery innards are a cylindrical roll. Getting the cells to fit together with adjacent cells kills cooling.

The cells are designed to optimize use in a Tesla car. Built to fit the battery compartment (or a dimensionaly altered one). Built to use the cooling system. Built to satisfy the V/I needs of their electronics. Get the longest range and shortest recharge time. Nothing else is relevant. They are not making consumer batteries. They may, as a side effect, create a standard for other things; but that is not the point. They are simply not bound to any standard. They will be big enough to cause any manufacturer that wants to be supplier to build whatever Elon wants. And it may become a standard. But he will not care. At his kind of usage level, it just is not his problem until demand exceeds his capacity. And at those levels, other manufacturers will build what he needs.

Debates about the cells are quite useless without knowing the structure and chemistry of the cells. There is no reason to assume the construction is like anything we have seen in production. Nor no reason to assume he will not use some esoteric technology. There are many proposed technologies out there. Elon does not back away from using advanced technology. 

The format and/or internals may show up in the commercial market at some point. Earlier if he can't get enough cars sold to keep his battery factory busy. He has also been very generous about making his designs open for free use. If he does that with batteries, that could allow some other manufacturers to make them as well. 

Short answer: we have no idea what he is doing, but it is not for flashlights.


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## vadimax (Aug 6, 2016)

FroggyTaco said:


> Per Elon Musk they decided to design a cell in the present as if there was no other existing format that would suit there needs. Apparently 21700 has the ideal capacity/discharge/charge/packaging specifications an electric car needs.
> 
> I would surmise a higher capacity 21700 cell would have less desirable discharge & lifecycle characteristics even if it would work amazing for us flashaholics.



Poor people. They still believe that switching to nonstandard form factor has something in common with optimizing. Elon Musk just wants bigger share of after sale revenue. It is the same as selling a car that consumes "proprietary" fuel.


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## oKtosiTe (Aug 6, 2016)

vadimax said:


> Poor people. They still believe that switching to nonstandard form factor has something in common with optimizing. Elon Musk just wants bigger share of after sale revenue.


It is entirely possible that both are true: better efficiency (whether cost-effective or otherwise) and Elon gets a bigger cut.



vadimax said:


> It is the same as selling a car that consumes "proprietary" fuel.


Nonsense. Whether the batteries in the car are 18650 or 2170, they are not user-accessible. It makes zero difference to the consumer if the cells use an old standard or a new one.



alternety said:


> Debates about the cells are quite useless without knowing the structure and chemistry of the cells. There is no reason to assume the construction is like anything we have seen in production. Nor no reason to assume he will not use some esoteric technology. There are many proposed technologies out there. Elon does not back away from using advanced technology.


Exactly. I have yet to see anyone here truly analyze this from an engineering point of view.


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## alternety (Aug 6, 2016)

Wrong site - sorry


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## PH1 (Oct 24, 2016)

There's also a Panasonic NCR20700*C* cell with a 3.5 Ah capacity under development: http://www.sdle.co.il/Default.asp?sType=0&PageId=56631
So capacity wise it sits in between the 3.3 Ah NCR20700*A* and the 4.25 Ah NCR20700*B*.


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## vadimax (Oct 25, 2016)

oKtosiTe said:


> It is entirely possible that both are true: better efficiency (whether cost-effective or otherwise) and Elon gets a bigger cut.
> 
> 
> Nonsense. Whether the batteries in the car are 18650 or 2170, they are not user-accessible. It makes zero difference to the consumer if the cells use an old standard or a new one.
> ...



Switching to battery format that is being produced by no one but you, you are free to rise those batteries' prices at will.


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## oKtosiTe (Oct 25, 2016)

vadimax said:


> Switching to battery format that is being produced by no one but you, you are free to rise those batteries' prices at will.


Teslas cars will still be competing with cars from other manufacturers, so I don't see why they would do that.
What remains to be seen is whether these new cells will be available to third parties and consumers (any time soon) in the first place. If they will, they will obviously have to compete with existing formats.


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## FroggyTaco (Oct 25, 2016)

vadimax said:


> Switching to battery format that is being produced by no one but you, you are free to rise those batteries' prices at will.



At this point the ONLY use for these cells is in their own vehicles so if they increased the price of the cells then they would be charging more for the vehicles they sell which is in direct competition with the rest of the comparable auto industry.

If anything they are spending enormous amounts of resources to make cell production cheaper so their vehicles will be cheaper & "better".

Not to mention in any capitalistic economy one will increase their prices(profits) if the market will reasonably bear it.

I'm also guessing this change will ultimately either render current Tesla battery packs obsolete or they will not benefit from future cell tech improvements such as the original Roadster is currently. 

I'm presuming that eventually the to be prior generation 18650 packs will still be available but at higher cost and lower capacity than what will become the new 20700 packs.


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## vadimax (Oct 25, 2016)

Do you remember anything "new" to come at a lower price than a previous version?


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## FroggyTaco (Oct 25, 2016)

vadimax said:


> Do you remember anything "new" to come at a lower price than a previous version?



Yes!. 

In the USA big screen LED TV's have gotten much larger & more features & better picture quality while also being cheaper. That industry also operates on massive manufacturing scale to lower costs & be more competitive like the auto industry.


I do however agree with your sentiment/point. However I will also rebuff your counter-point by stating that typically the said "new" thing offers an appreciably better experience that for the end user justifies the increased cost. As an example "summer" tires cost more than all seasons & last fewer miles(kilometers) however the massive increase in road grip/adhesion & other subtle tire behaviors are worth the "cost" for the then "new" technology the summer tire provides the end user.


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## StorminMatt (Oct 26, 2016)

Drift Monkey said:


> The funny part is that 18650s _still _have a better size to energy density ratio. The move to this new size must be purely to save money.


Maybe energy density is not really a priority. If it was, then why aren't Teslas currently using the NCR18650GA rather than lower capacity cells? I'm guessing that a MAJOR priority here is battery lifetime rather than capacity.


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## Lumencrazy (Oct 26, 2016)

vadimax said:


> Poor people. They still believe that switching to nonstandard form factor has something in common with optimizing. Elon Musk just wants bigger share of after sale revenue. It is the same as selling a car that consumes "proprietary" fuel.



Ever actually designed a battery?


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## Overclocker (Oct 27, 2016)

what's all this non-sense? gigafactory output is for internal use only. it doesn't matter what form factor they adopt coz you won't be able to buy it anyway


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## Lynx_Arc (Oct 27, 2016)

Overclocker said:


> what's all this non-sense? gigafactory output is for internal use only. it doesn't matter what form factor they adopt coz you won't be able to buy it anyway


In time most likely you will be able to buy them. I think two main factors could present themselves that would make this size battery compete head to head with 18650s in that laptop batteries made with 18650s are in decline possibly one day they won't even use that battery size in them at all, while power and yard tool and other consumer devices are adopting 18650 use if they are tempted by a higher per volume output (in use) battery type for cheaper in power that they could easily opt for 20700 over 18650 especially when 20700 batteries get "improvements" that other types don't get. If we see the 20700 suddenly superior to other sizes/types of batteries then their adoption in nearly everything could be widespread and 18650 batteries could become as hard to source as smaller sizes are and cost/power ratio could rise availability could fall as entire production lines dedicated to 18650s could be switched over to larger battery sizes. 
Personally I keep hoping for a breakthrough in battery technology to vastly improve everything and have double even triple the power in a safer type of battery that is useful for most applications. I would settle for even a higher voltage cell that lithium ion as it is typically easier (and safer) to drop voltages down than to add cells in series or boost drivers.


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## FroggyTaco (Oct 27, 2016)

I would like to add that I believe the majority of laptop batteries no longer us 18650 packs but rather Li-po packs that are rectangular & thinner that spread over a greater area of the laptop "footprint" for more energy density. At least for all the non-replaceable battery pack laptops.


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## Lynx_Arc (Oct 27, 2016)

FroggyTaco said:


> I would like to add that I believe the majority of laptop batteries no longer us 18650 packs but rather Li-po packs that are rectangular & thinner that spread over a greater area of the laptop "footprint" for more energy density. At least for all the non-replaceable battery pack laptops.


Yes the trend is thinner is better and the 18650 limits how thin you can make a laptop but as far as energy density 18650 probably has more to offer but makes designing thinner laptops a lot harder than using batteries half as thick.


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## TinderBox (UK) (Oct 28, 2016)

Interesting.

http://uk.businessinsider.com/materials-needed-to-fuel-electric-car-boom-2016-10

John.


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## Lumencrazy (Oct 30, 2016)

Is there one electro chemist, electronics engineer or materials scientist who has worked in battery research in this thread?


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## roger-roger (Nov 2, 2016)

[h=1]Tesla obliged to pay $1.7 billion to Panasonic for gigafactory cells[/h]
http://www.reuters.com/article/us-tesla-gigafactory-panasonic-idUSKBN12X1FR


Interestingly if the new factory will be producing the 20700, then it could very well be likely the configuration is proprietary.


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## kreisl (Nov 4, 2016)

NEWS 2016-11-04:*
Tesla Battery Cells Explode Like Fireworks In Video Of Fatal Crash
*http://www.jalopnik.com/tesla-battery-cells-explode-like-fireworks-in-video-of-1788573241


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## jstack6 (Nov 5, 2016)

They need cooling. It makes a big difference. You can get 20-30 years of life with cooling,even in a HOT area like Phoenix where I am. The Nissan LEAF has no cooling and batteries degrade 5-10% a year so after just 2 or 3 years they need to be replaced. Others like the Chevy SPARK EV , FORD Focus EV, and Tesla can have almost no capacity lost even after 2-4 years in the HEAT. a 20-30 year life at at least 80% capacity is possible. 



TinderBox (UK) said:


> Why are they going for cylindrical cells, would hexagonal cells pack more in the same space, or do they need a slight gap for cooling?
> 
> 
> 
> ...


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## roger-roger (Nov 6, 2016)

jstack6 said:


> They need cooling. It makes a big difference. You can get 20-30 years of life with cooling,even in a HOT area like Phoenix where I am. The Nissan LEAF has no cooling and batteries degrade 5-10% a year so after just 2 or 3 years they need to be replaced. Others like the Chevy SPARK EV , FORD Focus EV, and Tesla can have almost no capacity lost even after 2-4 years in the HEAT. a 20-30 year life at at least 80% capacity is possible.




Aren't the car batteries enclosed in a heat conducting matrix? Perhaps the cylindrical shape allows a smaller form factor for the battery pack, which gives adequate surface area for heat conduction.


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## vadimax (Nov 7, 2016)

Interesting moment: Li-Ion batteries need cooling, Li-Polymer (real Lithium-Polymer, not those Li-Ion that are not rolled in a cylindrical form and in order to fool customers being called Li-Po) are most effective at temperatures of 50-60°C.

Now is the question: what takes more energy -- cooling or heating up? Cooling is needed at charge-discharge stage, heating will be necessary while being idle (this is why real Li-Polymer batteries find no practical use, just their fancy name being used).


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## carl (Nov 15, 2016)

Which size is going to be the dominant one? The 20700 or the 21700?

Article: Huge leaps in e-bike battery capacity coming to e-bikes soon by Elliot Johnston Nov 4 2016.

http://ebiketips.co.uk/content/news/huge-leaps-in-e-bike-battery-capacity-coming-to-e-bikes-soon-428

"New, larger 21700 cell e-bike batteries from Samsung and German battery supplier BMZ, and a 20700 cell from Panasonic have pushed the envelope for e-bike power standards forward."

"Energy density is higher for the new cells, meaning that 700Wh batteries are likely to be commonplace by 2018."

"A 21700 cell can have a capacity of 4.8Ah, as opposed to 3.5Ah for an 18650 cell. "

"The unit also comes with high quality materials including stronger conductors and a greater proportion of active cell material which allows for a claimed 50% increase in energy supply and a 68% increase in output.

"...the development possibilities of the 18650 cell format are exhausted."


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## iamlucky13 (Nov 15, 2016)

vadimax said:


> Interesting moment: Li-Ion batteries need cooling, Li-Polymer (real Lithium-Polymer, not those Li-Ion that are not rolled in a cylindrical form and in order to fool customers being called Li-Po) are most effective at temperatures of 50-60°C.
> 
> Now is the question: what takes more energy -- cooling or heating up? Cooling is needed at charge-discharge stage, heating will be necessary while being idle (this is why real Li-Polymer batteries find no practical use, just their fancy name being used).



Tough call. When the ambient temperatures are lower than the ideal battery operating temp, which they usually are, cooling is easy. You just need to circulate coolant through the pack with a small pump, and into the radiator. You can easily move way more than a W-hr of heat for each W-hr of energy the pumps and fans consume. For heating, you get 1 W-hr of heat for each W-hr of energy consumed. However, once the pack is warmed up, the heat generated by the batteries in use helps keep it warm.


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## SubLGT (Nov 26, 2016)

Here is the first test I have seen of a 20700 battery, the Sanyo 4Ah 20700B cell:

https://www.e-cigarette-forum.com/f...nch-test-results-a-peek-at-the-future.775809/



> At 10A continuous it reached 3909mAh. This is good performance for a 4000mAh cell at 10A so I am rating it at 4000mAh.


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## 101010110011 (Nov 26, 2016)

vadimax said:


> Funny. They are going to produce batteries that are useless to us.


 What do you mean by that?


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## 101010110011 (Nov 26, 2016)

TinderBox (UK) said:


> Why are they going for cylindrical cells, would hexagonal cells pack more in the same space, or do they need a slight gap for cooling?
> 
> 
> 
> ...


 From the tesla battery packs I've seen, they run glycol between the cells. I think your right its needed for cooling.


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## vadimax (Nov 26, 2016)

101010110011 said:


> What do you mean by that?



You cannot stuff 20 or 21 mm battery into a 18 mm flashlight body


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## SubLGT (Nov 26, 2016)

vadimax said:


> You cannot stuff 20 or 21 mm battery into a 18 mm flashlight body



It is just as easy to manufacture a 20mm or 21mmm battery tube as it is to manufacture a 18mm tube.


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## SubLGT (Nov 28, 2016)

> …….Tesla opened its Gigafactory... to the surprising, if casual, announcement by Elon Musk that the Gigafactory will be three times the original 50GWh planned capacity……
> 
> …...The real concern now is whether there will be enough raw material to fuel not only a 150GWh Gigafactory but also the major growth that is being seen in China where at least 7 lithium ion megafactories are being built.
> 
> …….The answer is no.



http://benchmarkminerals.com/Blog/tesla-faces-raw-material-reality-with-expanded-gigafactory/


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## vadimax (Nov 28, 2016)

I am not sure about source reliability, but one of TFLCars interviews mentioned 100 mm long batteries:


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## Overclocker (Nov 29, 2016)

who wants another size


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## Overclocker (Nov 29, 2016)

.......................... d/p


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## carl (Dec 1, 2016)

SubLGT said:


> It is just as easy to manufacture a 20mm or 21mmm battery tube as it is to manufacture a 18mm tube.



I hope flashlight makers keep their battery tubes as close as possible to 1 inch outer diameter to maintain compatibility with standard 1 inch mounting devices (even if the threaded tailcap area needs to be bigger).


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## carl (Dec 1, 2016)

The 20650 is an oddball size. 

Its going to be either 20700 or 21700.


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## fivemega (Dec 1, 2016)

carl said:


> The 20650 is an oddball size.
> 
> Its going to be either 20700 or 21700.



*Most protected 18650 cells have diameter of close to 19mm and length of 68~69mm so 20650 will be 21x70mm (size of 21700).*


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## carl (Dec 2, 2016)

You're probably right. 

Standard bare cell unprotected: 20650

Hi-capacity with protection circuit: 21700

Actually, the Tesla Gigafactory is probably going to produce a standard bare cell using the 21700 dimensions or something very close to it. Others will come along and repackage it with their own thick wrapper and a protection circuit which will result in an even bigger overall cell but the capacity will remain unchanged.

With the greater potential for advancements with this new battery, I guess this means 'buh-bye' to the 26650, at least for flashlights.


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## carl (Dec 8, 2016)

In stock already?

http://www.illumn.com/20700-sanyo-ncr20700b-high-discharge-flat-top.html

20700 Sanyo NCR20700B High Discharge Flat Top

SKU:Sanyo NCR20700B 

Availability: In Stock

$9.99 

PRODUCT DETAILS

SANYO NCR20700B 4250 mAh High Discharge Flat Top 

Specifications:
Nominal Capacity: 4000 mAh
Typical Capacity: 4250mAh
Nominal Voltage: 3.7V
Standard Charging Current: 2A
Discharge End Voltage: 2.5V
Max Continuous Discharging Current: 12A
Weight (max): 63.0g

Dimensions:
70.3mm (L) x 20.35 mm (D)


With these kinds of performance numbers above, and at this early stage of development, with a little more development this cell is going to supercede the performance of a 26650 in the near future!


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## SubLGT (Dec 9, 2016)

Who will be the first to manufacture a flashlight that accepts the Sanyo 20700 (without using an adapter)? Nitecore? Armytek? Zebralight? Fenix?


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## Enderman (Dec 9, 2016)

vadimax said:


> I am not sure about source reliability, but one of TFLCars interviews mentioned 100 mm long batteries:







40152 is also one of the most popular for electric vehicles


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## stephenk (Dec 9, 2016)

With the possibility of protected and unprotected versions of 20650, 20700, and 21700, expect the "these cells don't fit in my light" problems to get worse.


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## SubLGT (Dec 9, 2016)

I wonder if Samsung will be using a 21700 cell in an automotive application?



> Samsung SDI and luxury EV startup Lucid Motors have entered a strategic partnership for battery cell supply. Samsung SDI will be a major supplier of lithium-ion cells for Lucid’s first vehicle, an electric executive sedan scheduled to begin production in late 2018.
> 
> Samsung SDI and Lucid have collaborated to develop next-generation cylindrical cells that are able to exceed current performance benchmarks in areas such as energy density, power, calendar life and safety. Significantly, this jointly developed cell also achieves breakthrough tolerance to repeated fast charging.



http://www.greencarcongress.com/2016/12/20161206-lucdi.html


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## SubLGT (Dec 19, 2016)

The 21700 format seems to be gaining some traction.

http://www.bike-eu.com/home/nieuws/...y-innovations-presented-at-eurobike-10127504#



> BMZ, which is Europe’s biggest battery supplier not only for e-bikes but also for tools, household and gardening appliances, announced its ‘true quantum leap’ in e-bike battery technology in Friedrichshafen…………………..
> 
> Europe’s biggest battery supplier says, “With 3Tron, BMZ is putting its trust in a completely new format: instead of a 18650 (18mm diameter and 65mm high) cell size, 3Tron will be produced as a size 21700 cell (21mm diameter and 70mm high)…………….
> 
> ...it is clear that other manufacturers will follow and produce 21700 format batteries as well: the development possibilities of the 18650 cell format are exhausted.”……………...


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## StandardBattery (Dec 19, 2016)

SubLGT said:


> Who will be the first to manufacture a flashlight that accepts the Sanyo 20700 (without using an adapter)? Nitecore? Armytek? Zebralight? Fenix?


I'm hoping it's ZebraLight. Got a few of these batteries, but have not tested them yet.


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## SubLGT (Dec 20, 2016)

More about the BMZ battery pack using 21700 cells:



> BMZ’s new 3Tron battery with cells in the 21700 format sets new standards in terms of capacity and discharge current…………...Sven Bauer, Managing Director of BMZ GmbH in Karlstein am Main is enthusiastic about the new cell: “Its usable battery capacity is several times that of conventional cells in the 18650 format: you have 60 percent more capacity while being able to use 400% more discharge current at the same time.”……...In producing the super cell, BMZ cooperates with the world's leading cell manufacturer Sony. Its manufacturing expertise with more than 300 million cells annually guarantees top quality. The assembly of the 3Tron batteries will take place at BMZ - Europe's new gigafactory. With a footprint of 55,000 m2, it is Europe's largest battery factory…..



http://www.bmz-group.com/dokumente/...BMZ_PM_Tritrion_Kapazitaet_-21_09_2016_EN.pdf


So, this Sony/BMZ 21700 cell has 60% more capacity and 400% more discharge current than a 18650 cell. Sounds like a big upgrade to me.


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## Enderman (Dec 20, 2016)

SubLGT said:


> More about the BMZ battery pack using 21700 cells:
> So, this Sony/BMZ 21700 cell has 60% more capacity and 400% more discharge current than a 18650 cell. Sounds like a big upgrade to me.


This is simply due to better manufacturing and battery improvements, there is nothing magical about the 21700 size.
It's just a size between 18650 and 26650.
If they used this improved manufacturing for 18650 or 26650 cells you would also see more capacity and higher discharge.


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## kreisl (Dec 21, 2016)

BU-301a said:


> There is talk about a new Li-ion cell format with dimensions of 20700, 21700 and 22700. Meanwhile, Tesla, Panasonic and Samsung have decided on the 21700 for ease of manufacturing, optimal capacity and other benefits. While the 18650 has a volume of 66cm3​ with a capacity of around 3000mAh, the 97cm3​ volume of the 2170(0) is said to produce a capacity of up to 6000mAh, essentially doubling the capacity with a 50% increase in volume. Tesla Motor refers to their company’s new 2170 as the “highest energy density cell that is also the cheapest.”



a quote from BatteryUniversity.com book chapter.

interesting.

Also check out episode S01E03 of Good Behavior ... kinda tricky to find a refueling station


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## lumen aeternum (Dec 31, 2016)

TinderBox (UK) said:


> Great video, over 7000 18650 cells in the car power pack, But will we CPF ever see the improvements in battery capacity that Tesla make or will it be a guarded secret, now they are making their own 20700 cells in the US.
> John.



So how long is it going to take the typical CPFer to dis-assemble and test a used car power pack in order to cull out the good cells?

Maybe make a group purchase and share the cell packs?


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## SubLGT (Jan 2, 2017)

Enderman said:


> ... there is nothing magical about the 21700 size.
> It's just a size between 18650 and 26650...



Is the 18650 size magical?


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## fivemega (Jan 2, 2017)

SubLGT said:


> Is the 18650 size magical?



*There are many flashlights, other devices and universal holders currently made and available for this size.
It will take several years for them to switch to new size if they find any significant improvement and lower cost.*


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## SubLGT (Jan 4, 2017)

Production of 21700 cells has begun today, at the Gigafactory.
https://www.tesla.com/blog/battery-cell-production-begins-gigafactory


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## vadimax (Jan 4, 2017)

SubLGT said:


> Is the 18650 size magical?



Yes. Because of huge market of 1" gun mounts.


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## vadimax (Jan 4, 2017)

What battery format did he show?


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## moozooh (Jan 4, 2017)

As per http://www.autonews.com/article/201...ure-demonstrates-powerful-ev-despite-setbacks:



> The battery cells are supplied by LG Chemical and use the forward-looking 21700 cells (as opposed to the more common 18650 cell), which Faraday Future said it expects to have the highest energy density of any in the auto industry.



I think at this point we can safely assume that in less than a year 21700 will become the de facto standard for EVs.



vadimax said:


> Yes. Because of huge market of 1" gun mounts.


1" = 25.4 mm, which is still 4.4 mm wider. If a flashlight manufacturer opts to use a 21700 cell in a flashlight intended for potential gun mounting, I expect they take that into account and avoid bloating the battery tube. It's doable.


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## StandardBattery (Jan 4, 2017)

moozooh said:


> As per http://www.autonews.com/article/201...ure-demonstrates-powerful-ev-despite-setbacks:
> 
> 
> 
> ...



Yup, and that means the cells will also migrate to other industrial uses.

Maybe a new 21350 cell will eventually appear as the 18350 didn't make many inroads. A 21350 I'm sure would be a very nice cell format for flashlights.


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## vadimax (Jan 5, 2017)

moozooh said:


> 1" = 25.4 mm, which is still 4.4 mm wider. If a flashlight manufacturer opts to use a 21700 cell in a flashlight intended for potential gun mounting, I expect they take that into account and avoid bloating the battery tube. It's doable.



It is not  Having only 4.4 mm we should reserve 1 mm for protected/rewrapped cells. After that only 1.7 mm of wall thickness is left for knurling, threaded connection. Who on Earth would mount a light which body is foil thin and may be crushed with fingers?


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## moozooh (Jan 5, 2017)

vadimax said:


> It is not  Having only 4.4 mm we should reserve 1 mm for protected/rewrapped cells. After that only 1.7 mm of wall thickness is left for knurling, threaded connection. Who on Earth would mount a light which body is foil thin and may be crushed with fingers?


You're reasoning under the erroneous assumption that a 1" flashlight mount requires the _entire_ battery tube, including the cap, to be 1" thick. This is simply not the case—only the small part that goes into the mount has that requirement. For the record, 1.7 mm is still a thicker wall than a typical laser scope has (last I checked). Some manufacturers of tactical flashlights also make their own mounts, so it's not a big deal either way.


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## Kirbz252 (Jan 5, 2017)

Tesla released this teaser style video a few days back. Pretty cool seeing what goes into battery production.

https://www.facebook.com/tesla/videos/10154876472132801/

Look at all those shiny 2170 cells *drools*

Dave


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## SubLGT (Jan 6, 2017)

Quoted from https://www.dal.ca/diff/dahn/news.html 



> June 8, 2016
> NSERC, Dalhousie University and Tesla Motors have established the NSERC/Tesla Canada Industrial Research Chair that Jeff Dahn will hold from June 8, 2016 to June 7, 2021. It is possible that the Chair will be renewed in 2021. The goals of the Chair are to develop lithium ion batteries with longer lifetime, higher energy density and lower cost. As Dahn says, "Our goal is to do something useful, not publish papers in Nature and similar journals".



The last sentence made me chuckle.

So far, I have not seen any information from Tesla or Panasonic about the capacity of the 21-70 tesla cell, only the claim that it has the "highest energy density and lowest cost of any cell on the planet". The quantity of 5750mAh has been mentioned on forums, but no verification was provided.


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## StandardBattery (Jan 6, 2017)

SubLGT said:


> Quoted from https://www.dal.ca/diff/dahn/news.html
> 
> 
> 
> ...


That last sentence is funny. LG has been claiming the same "highest energy density" for their 21700 battery as well. No details that I have found yet. I think we can just wait to see what is the energy of the next battery-pack that Tesla announces. That might be where the 5750mAh number is coming from I have not been following it that closely. Just waiting until I can actually get some batteries, but that might be a while.


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## Dubois (Jan 6, 2017)

Sorry, HKJ's review already posted


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## carl (Jan 7, 2017)

https://www.imrbatteries.com/sanyo-ncr20700a-3100mah-30a-flat-top-battery/

Sanyo NCR20700A: 3100mAh, 30A, $10/unit
Sanyo NCR20700B: 4000mAh, 15A, $10/unit


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## vadimax (Jan 7, 2017)




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## SubLGT (Jan 10, 2017)

Samsung displayed their 21700 cell at the 2107 North American International Automobile Show, but did not provide technical details.

https://electrek.co/2017/01/09/samsung-2170-battery-cell-tesla-panasonic/


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## SubLGT (Jan 15, 2017)

Overclocker said:


> who wants another size



Apparently, this 20650 size is being used in a Dewalt 20V battery pack. There is also a version rated at 4200mAh and 15A.


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## StandardBattery (Jan 15, 2017)

SubLGT said:


> Apparently, this 26650 size is being used in a Dewalt 20V battery pack. There is also a version rated at 4200mAh and 15A.


Did you mean 2*6*650 or 2*0*650? 

I have one of the 20V packs I got for free sitting here to open up, but it's one of the smaller 2Ah/40W ones. I'm debating first if i should put it on my charger or drill first, or just strip it and avoid any possible damage to the devices. The chargers are pretty robust, so I might risk it, but I am interested to see what's inside although it is a smaller pack.


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## SubLGT (Jan 15, 2017)

Yes, a typo. Corrected. 

The tiny photo I saw of the 20650 20V Dewalt battery was for the 3.0Ah 5S1P pack. It's overall size was about half of the 20V Dewalt 18650 3.0Ah pack.

If you scroll half way down the linked pdf document, you can see it:
http://www.emove360.com/wp-content/...Report-ver-3-presentation-for-conferences.pdf


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## SubLGT (Jan 15, 2017)

Tesla R&D might be pursuing a higher voltage Li-ion cell. Jeff Dahn will be discussing it:

http://www.internationalbatteryseminar.com/battery-research/



> *Surprising Chemistry in Li-Ion Cells*
> _Jeff DahnJeff Dahn, Ph.D., FRSC, Professor of Physics and Atmospheric Science, NSERC/Tesla Canada Industrial Research Chair, and Canada Research Chair, Dalhousie University_
> "It is important to increase the operating voltage of NMC Li-ion cells to obtain higher energy density. However, the electrolyte reacts with the positive electrode at high voltage. Using simple experiments involving only pouch bags, we show that the products of these reactions are extremely harmful to the positive electrode. This talk demonstrates how these harmful reactions at the positive electrode can be virtually stopped, leading to superb NMC Li-ion cells that can operate at high potential."


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## SubLGT (Apr 10, 2017)

> ...The success of Tesla and its Nevada-based Gigafactory facility has generated a lot of excitement in the LIB industry. Panasonic’s automobile battery sales are forecast to grow to $4 billion a year by March 2019, largely due to their partnership with Tesla.
> 
> “We think the existing technology can still extend the energy density of LIBs by 20% to 30%,” Panasonic’s President Kazuhiro Tsuga said. “But there is a trade-off between energy density and safety. So, if you look for even more density, you have to think about additional safety technology as well. Solid-state batteries are one [possible] answer.” These safety concerns about LIBs are also pushing Panasonic to look at alternative battery power sources.
> 
> ...



https://www.teslarati.com/tesla-partner-panasonic-20-30-percent-energy-density-increase/


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## SubLGT (Apr 20, 2017)

https://electrek.co/2017/04/20/tesla-gigafactory-nevada-lt-gov-tourist-attraction-chinese/



> Nevada’s Lt. Gov. Mark Hutchison recently went on a trade mission to China to promote tourism and his “biggest takeaway” from the mission is surprising: touring Tesla’s Gigafactory was a “near-constant theme” brought up by Chinese tourism officials.



Hmmm. "Tourism officials" ?


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## SubLGT (Jul 27, 2017)

Is Tesla dropping the 21700 cell for the new Model 3 battery pack, in favor of a rectangular format cell, called the 4416 ?????

That is the claim being made here:
http://gas2.org/2017/07/24/source-tells-teslanomics-tesla-using-44160-cells-model-3-battery-packs/



> Tesla began manufacturing so-called 2170 battery cells at the Gigafactory in Nevada last year... Until this point, it was assumed that Tesla would utilize the 2170 cells to make the battery packs for the Model 3. But if Ben Sullins’ source is correct, the Model 3 battery pack will actually used battery cells that are 44 millimeters high and 16 millimeters wide….
> 
> Ben Sullins of Teslanomics has created a thriving business by reporting on all things Tesla and doing it in an authoritative fashion. When you get recognized as an authority, people tell you things that they don’t tell others. Right now, Sullins say he has a source that is “very close to Tesla” who is telling him the battery pack in the new Model 3 due out on Friday will use a brand new lithium ion cell format...



https://teslanomics.co/new-model-3-battery-cells


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