Sanyo NCR20700B 4250mAh cell is here!

Sanyo NCR20700B 4250mAh cell pdf is here:
http://akkuplus.de/mediafiles/Datenblatt/Panasonic/Panasonic_NCR20700B.pdf
Current price in EU is 14€/piece, but it is expected to drop soon.

Specifications
Rated capacity 4000mAh.
Minimum capacity 4050mAh.
Typical capacity 4250mAh.
Charging voltage 4.2V.
Std charging current 2A.
Mass 63 g.

According to the pdf file I_absolute_max is 20A/cell, and I_recommended is 8A/cell or less. At 12A, capacity drops over cycle time too much to be practical in ebike use.




View attachment 1

For 20A use, there is Sanyo NCR20700A. A version has less capacity than B version (3.1Ah~3.3Ah vs 4Ah~4.25Ah), but I_max=30A short burst. Pdf of the A version is here http://akkuplus.de/mediafiles/Datenblatt/Panasonic/Panasonic_NCR20700A.pdf

It seems this cell has about 92% of the energydensity the 18650 GA cell has.
Did fast and dirty calcs with 48g and 63g for mass (claimed maximum in spreadsheets), and with 3300mAh and 4000mAh capacities (rated in spreadsheets).

I find this new format to be very interesting. But isn't tesla going for the 21700 format?
Wonder why they settle on different sizes...?

Anyone know if these new 20700 cells have the same can thickness as the 18650?

Wheazel said:

I find this new format to be very interesting. But isn't tesla going for the 21700 format?
Wonder why they settle on different sizes...?

Click to expand...

I believe that Tesla always calculated with 20700 format, because the 21700 is already much bigger than 18650 and so you have problem with maintaining energy density close to 18650.

Simply said with today's battery technology the 18650 cylindrical format still forms a narrow peak with the highest available energy density. Any other cylindrical format (bigger or smaller) loses its energy density exponentially. For example today's best 18500 or 26650 achieves only 550Wh/l, which is equal to best modern pouch cells (eg. LG pouch cells used in GM Bolt) and so there is no benefit to use them. Even new Samsung 21700 cells are below 600Wh/l.

Wheazel said:

Anyone know if these new 20700 cells have the same can thickness as the 18650?

Click to expand...

You mean can wall thickness? If so, I don't know.

Wheazel said:

....
Anyone know if these new 20700 cells have the same can thickness as the 18650?

Click to expand...

.? Im curious as to why this might be of any interest ?.....
...but as an experienced guess i would say Yes.
I would be very surprised if they are not basicly the same wall thickness as far as you or i can measure ( +_ 0.005mm). The can base may well be slightly thicker to retain internal pressure resistance.

Wheazel said:

I find this new format to be very interesting. But isn't tesla going for the 21700 format?
Wonder why they settle on different sizes...?

Click to expand...

According to Musk the 20700 cells has 30 % more energy density then 18650's yet adds only 10% to the bulk.
Tesla will be using 20700, at least that was stated by Musk earlier this year when he spoke in Oslo. And reason was that only 20700 size would bring enough energy in a small enough package without increasing the bulk or pack size, and weight.

I wonder when okashira gets his hands on the first salvaged Tesla 20700 battery pack.

Something tells me that we have to wait until the launch of the Model 3.

Hillhater said:

Wheazel said:

....
Anyone know if these new 20700 cells have the same can thickness as the 18650?

Click to expand...

.? Im curious as to why this might be of any interest ?.....
...but as an experienced guess i would say Yes.
I would be very surprised if they are not basicly the same wall thickness as far as you or i can measure ( +_ 0.005mm). The can base may well be slightly thicker to retain internal pressure resistance.

Click to expand...

Because if the structural strength is enough with the same wall thickness, another small advantage for the 20700.
It is minor, but everything helps when hunting E density.

macribs said:

Wheazel said:

I find this new format to be very interesting. But isn't tesla going for the 21700 format?
Wonder why they settle on different sizes...?

Click to expand...

According to Musk the 20700 cells has 30 % more energy density then 18650's yet adds only 10% to the bulk.
Tesla will be using 20700, at least that was stated by Musk earlier this year when he spoke in Oslo. And reason was that only 20700 size would bring enough energy in a small enough package without increasing the bulk or pack size, and weight.

I wonder when okashira gets his hands on the first salvaged Tesla 20700 battery pack.

Click to expand...

Do you know if Musks E density statements refer to the bare cell, or Teslas complete battery design with each celltype?
Cause if it's the bare cell -> happy days
Or complete package -> other improvements/material savings represent some of the leap forward.

No sorry I can't be sure, can't remember more then what I wrote. But I guess the number one reason for taking the leap from 18650 and over to 20700 is that higher energy density will mean the cost of producing each battery pack will be smaller for Tesla, but what is good for their bottom line is in this case also good for us, more capacity also for e-bikes eventually.

What seems to be the problem now in the early stages of 20700 cells is to find a trustworthy seller of those 20700 cells. So far I've yet to see any of the few trusted 18650 vendors stock their inventory with 20700 cells. Guess price is still too high really create a demand for 20700 right now.

@Pajda no I don't think Tesla will wait for the model 3 before introducing the 20700 cells. Because the giga factory will be up running late this fall and I think they will ease into the new cells ie with launching M/S-X 100 and possible M S/X 120kw later this fall, early next year. Also the main reason for the switch in cell size is reduced costs for Tesla, why waste time slashing production and manufacturing costs?

My opinion is based on the assumption that 20700, resp. 21-70 is a very new technology.

The first samples have appeared only about six months ago. Series production runs most probably only in Japan and the question is how many 21-70 cells is Panasonic able to produce right now. Gigafactory is still not finished and it would take a time to start effective mass production of this state of the art technology.

Also I see a problem in known parameters of today available 20700 and 21700 samples. Their volumetric density is significantly lower than 18650 cells already used in 90kWh battery. So it seems to me almost impossible to design a 100kWh battery with them. But for expected Model 3 battery capacity their parameters are sufficient.

Anyway I hope that we will know the details soon...

We wont know for certain until cells are physicaly available, but the latest reports all point to a 21700 cell from Tesla..
http://www.gizmodo.com.au/2016/08/teslas-new-gigafactory-in-nevada-is-finally-open/

..... Tesla also revealed the design of a new battery cell that it has been working on for some time, using newer battery chemistry and a size and diameter that optimises the internal capacity against the materials that surround it. Batteries — which are cylindrical because the cathode and anode are deposited in a sheet that is then rolled — are defined by their diameter and length, and the new ’21-70′ or 21700 battery is both larger and longer than the common 18650 cell already used in Tesla’s current cars and countless laptop batteries worldwide....

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Oh well 20700 or 21700 does not really matter for us e-bikers. The extra capacity and hopefully even better discharge rate will be much welcome whatever the diameter of the cells, as long as they can force enough energy into those things.

Anyways I feel the market is ripe for even higher rated cells, seeing as both the EV grows in various directions, and there is new markets like vaping of e-cigarettes etc.

More and more companies are looking long and hard for a way to adjust to the new reality, sometimes it feels like the mid nineties and the e-com and web hysteria all over. We sure need that extra cravings to have manufacturers push even harder to get every drop of energy out of todays battery technology.
Just in the last few months we have gotten several new companies to the market doing e-buses, e-delivery vans, e-tractors and even 4x4 ATV's those side by side ones. It also was some news about Tesla taking delivery of several tons of samsung batteries, and that they have widen their horizon in regards to battery manufacturers. According to rumors even more vendors have had sit downs with Tesla lately. Seems Panasonic will have to struggle hard to keep their exclusive with Tesla now that Musk is revving up and gearing production volumes up ten times per year from todays yearly production run. Or it could be Tesla will use other manufacturers for their home battery stations.

One thing is for sure, there will be some companies that will rise to the moon and other will take a dive in their stock price. Some will make it big and others might end up like the automotive or energy sectors Kodak.

I doubt Panasonic are concerned about their Tesla sales, as they have a "partnership" with them in the GigaFactory , having supplied the equipment and technology for cell manufacture, and will effectively be operating the cell production facility on that site.
Obviously sufficient "financial arrangements" are in place such that Panasonic get a suitable return on their investment.
Its not good business practice for a company to have "sole supplier" agreements for critical components. Its common practice to develope secondary sources ( even if the cost is higher) , as insurance for unforseen events.

Who are the Trusted Sellers/Vendors of the current 18650's by Panasonic/Sanyo , Lg, in particular the Panasonic/Sanyo GA 3500 Mah cells ... Here in the U.S. / North America ?

Your experience and pricing and shipping costs ?

Also

Does Okashira sell new cells ? what is his website ?

Thanks

macribs said:

What seems to be the problem now in the early stages of 20700 cells is to find a trustworthy seller of those 20700 cells. So far I've yet to see any of the few trusted 18650 vendors stock their inventory with 20700 cells. Guess price is still too high really create a demand for 20700 right now.

Click to expand...

Interesting. Not really any more dense per cubic cm/inch/litre though than the current 18650 3.5ah cells?
A circle is always 78.5% of a square that bounds it.

Samd said:

Interesting. Not really any more dense per cubic cm/inch/litre though than the current 18650 3.5ah cells?
A circle is always 78.5% of a square that bounds it.

Click to expand...

Reminds me of a forestry manager who was delighted to find a strong correlation between the diameter of a tree and the volume of wood... :lol:

Samd said:

Interesting. Not really any more dense per cubic cm/inch/litre though than the current 18650 3.5ah cells?
A circle is always 78.5% of a square that bounds it.

Click to expand...

Very true Samd, ...but each cell has 45% + more volume (and presumably capacity , potentially? )
...which means proportionally less connections, reduced assembly time, etc, ....for similar capacity packs.
So useful for gains in production eficiency and cost reduction.

No doubt my friend.
But the view that it offers a significant change in density is incorrect.

Although per unit length there'll be a small gain in the percentage taken by terminations. And I hate welding so less welds is good.
But its not really any great leap in density.

....But its not really any great leap in density

Click to expand...

No. That would need a improvement in chemistry.
My guess is these Sanyo NCR20700B is using the same tech as the 18650B .
But , since Tesla has just upgraded their pack capacity 11% to 100kWhr, (still using 18650 cells ?) i wonder if there is a new chem/tech in play already.?
https://www.tesla.com/blog/new-tesla-model-s-now-quickest-production-car-world

.....The new battery module is roughly the same shape and size as the 90 kWh version, though it's more densely packed and features improved cooling mechanisms. The standard charging rate for the 100 kWh battery remains the same as its predecessor, while supercharging should hold a higher rate for a longer period of time.

Click to expand...

Hillhater said:

Samd said:

Interesting. Not really any more dense per cubic cm/inch/litre though than the current 18650 3.5ah cells?
A circle is always 78.5% of a square that bounds it.

Click to expand...

Very true Samd, ...

Click to expand...

not all that true actually
it approaches 86.6%
one half root three

IF the goal is packing density
THEN you'll honeycomb instead of brick-lay

I am keen to keep track of these new developments as they unfold, however...I suspect it will be very difficult to get our collective hands on any of these in any quantity for quite some time. If Tesla is truly making these for their cars (and the power-walls), then the initial years production will most likely be unobtainium.

My research has shown me that the high-volume and high-current cells we ebikers crave are in a market driven by cordless tools (less than an hour ago, I used my 14S string-trimmer/weed-wacker). Laptop computers still use 18650's, but those are low-current, and compete on lowest wholesale price. I am willing to stick my neck out and predict that for the next year (at least) our best bang-for-the-buck will remain the 18650-format.

Toorbough ULL-Zeveigh said:

not all that true actually
it approaches 86.6%
one half root three

IF the goal is packing density
THEN you'll honeycomb instead of brick-lay

Click to expand...

Honeycomb lay is called face-centered cubic in battery design. Unfortunately the formula for face centered cubic yields the same result for the interior area - whether it is 18mm diameter or 20mm diameter.
Try the face centered cubic forula here - you will see. http://www.powerstream.com/BPD.htm

In fact 18mm cells give better end fill than 20mm losses.

i think what Elon Musk really meant is that on the wide layout machine for lithium substrate, by going to 70mm tall cells and 20mm wide, less of the sheet goes in the bin. And there is less welding.
But you don't fit more cells in a cubic litre of onboard storage.

And the vendors/sellers of Genuine Panasonic GA cells and the other Quality 18650 cells that are over 3100 mAh , here in the U.S.A. is / are .... Who ? ( luna only has 2500mAh cells, the INR 25R )

What prices did you find ?

Shipping costs for how many ?

Does Okashira have a website, does he only sell salvaged tesla cells ?

spinningmagnets said:

My research has shown me that the high-volume and high-current cells we ebikers crave are in a market driven by cordless tools (less than an hour ago, I used my 14S string-trimmer/weed-wacker). Laptop computers still use 18650's, but those are low-current, and compete on lowest wholesale price. I am willing to stick my neck out and predict that for the next year (at least) our best bang-for-the-buck will remain the 18650-format.

Click to expand...