NCM cells

[Torti]

Does anyone have experience with these cells?




I want to build a 72 volt battery.
I want to build an enduro and ride it off-road.



I've also considered using 18650, but I don't know if they can take it.
In difficult terrain, I know there are cell holders, but I don't think they're good for a crash !?

 

[Pajda]

It seems to be VDA-PHEV2 prismatic format with: 27x147x91mm dimensions (91mm is height without the screw terminals). In this particular format you can get 50Ah (some producers claim 53Ah) as "high energy" cell (1C/1C at 100% DoD with >1000cycles life) and 37Ah (some producers claim 42Ah) as "high power" cell (2C/2C at 100% DoD with >1000cycles life).

The energy desity is ca 450Wh/l and 200Wh/kg for 50Ah HE cell. There are already many producers in China of this particular format and usually even nonames have good quality.

 

[999zip999]

Pajfa how you know that one wow.

 

[Hillhater]

Does anyone have experience with these cells

If that is a photo from Ebay/Alibaba/etc....remember you may not get what you see.
Do you have an actual spec sheet and confirmed quote.?

 

[amberwolf]

If that is a photo from Ebay/Alibaba/etc....remember you may not get what you see.

It's not even a photo--it's just a basic cgi 3d rendering.

Does anyone have experience with these cells?
I want to build a 72 volt battery.
I want to build an enduro and ride it off-road.
I've also considered using 18650, but I don't know if they can take it.
In difficult terrain, I know there are cell holders, but I don't think they're good for a crash !?

@Torti; since you don't link to the actual cells, there's no way anyone (even Pajda) can know what those cells are or their specs (at least, what the vendor *says* their specs are)--it's just a guess, at best.

And since we don't know what kind of power demands your bike will have, we also can't know if the cells would be appropriate.

SInce we don't know how big a battery case or spot your bike has, *and* we don't know how big the cells are, we can't know if the cells will fit.

Etc.

You must provide us complete information for us to help you.

 

[Torti]

I found a manufacturer in Germany that can supply a 72AH cell.


I want to run 5000 watts with 200A power.
I will adjust the frame for the battery.

 

[Pajda]

If that is a photo from Ebay/Alibaba/etc....remember you may not get what you see.

It's not even a photo--it's just a basic cgi 3d rendering.


@Torti; since you don't link to the actual cells, there's no way anyone (even Pajda) can know what those cells are or their specs (at least, what the vendor *says* their specs are)--it's just a guess, at best.

And since we don't know what kind of power demands your bike will have, we also can't know if the cells would be appropriate.

SInce we don't know how big a battery case or spot your bike has, *and* we don't know how big the cells are, we can't know if the cells will fit.

Etc.

You must provide us complete information for us to help you.

Do not underestimate uncle Pajda so easily... :wink:

I am guesing that it is ETC-NCM72A cell, here you can find the datasheet https://www.lithiumstorage.eu/Joomla/index.php/en/produkte-lithium-storage/lithium-batterien-etc-series/ncm72ah.html It is modified VDA-PHEV2 format, just wider (40mm wide) and so energy density is the same as in 50Ah model (27mm wide). They are using the same picture/3D model for both. Anyway the chemistry and the internal design is the same. I have tested a 50Ah version, maybe from the same factory, and the results are very good in both cycle life and DCIR.

I think it will work in your application well. 72V battery at 1C gives you 5000W. Those cells are very robust, they are rated as 1C continuous discharge and even charge at 100% DoD. They will work well even without thermal management (VW used their 37Ah and 25Ah predecessors in eGolf and e-UP! this way) You are paying for it with worse energy density, particularly the volumetric one.

 

[Balmorhea]

It seems to be VDA-PHEV2 prismatic format with: 27x147x91mm dimensions (91mm is height without the screw terminals). In this particular format you can get 50Ah

I’m interested to find either the 37Ah or the 50Ah version of these cells for sale. i have a pack I built from the 25Ah cell, and it’s old and tired enough that i think it’s probably delivering less than 15Ah. Either one of these new variants would be a huge upgrade (and I’d be able to reuse my bus bars, wiring, compression, and BMS).

 

[Hillhater]

...I want to build a 72 volt battery....
.....I found a manufacturer in Germany that can supply a 72AH cell.
......I want to run 5000 watts with 200A power.

You need to clarify exactly what you “want”..
Why do you “want” 200A ?
200A at from a 72v pack would be 14,000 watts !..
.......and need about 60 of those 72Ah cells ..(or the 42Ah cells if they are 2C !)....and weigh 80+kg
BUT...5000 Watts would only need 20 of hte 72Ah cells ! Running at 72A ! At a more “reasonable” 25kg .
So ,... review your needs , 72v ?...200A ?, ..5000W ?..

 

[amberwolf]

I found a manufacturer in Germany that can supply a 72AH cell.

Why not link us to the cell so we can actually get the specs?

Why not tell us exactly what you really want to do, in detail?

If you don't tell us the required information, we can only guess, and if we're wrong, and you build based on that wrong info, you don't get what you want, and you just wasted everyone's time.

If you want to get the right stuff, help us help you.


Otherwise you might as well just buy whatever the heck you feel like, and see what happens.

It's your money.

 

[john61ct]

Yes, actually manufactured in Germany?

Please link.

 

[john61ct]

It seems to be VDA-PHEV2 prismatic format with: 27x147x91mm dimensions (91mm is height without the screw terminals). In this particular format you can get 50Ah (some producers claim 53Ah) as "high energy" cell (1C/1C at 100% DoD with >1000cycles life) and 37Ah (some producers claim 42Ah) as "high power" cell (2C/2C at 100% DoD with >1000cycles life).

The energy desity is ca 450Wh/l and 200Wh/kg for 50Ah HE cell. There are already many producers in China of this particular format and usually even nonames have good quality.

Great stuff Pajda. Have you got any info on reliable makers of quality LFP in that form factor? I realize energy density will be lower.

 

[Hillhater]

Not Lfp, but LTO, a very similar format cell from gs-yuasa, the LEV50N cell was used in Mitsubishi iMev and Outlander PHEV with a claimed cycle life of 5500 cycles 100% DOD and capable of 6c discharge.
https://pushevs.com/2015/11/04/gs-yuasa-improved-cells-lev50-vs-lev50n/

 

[Honk]

I am guesing that it is ETC-NCM72A cell, here you can find the datasheet https://www.lithiumstorage.eu/Joomla/index.php/en/produkte-lithium-storage/lithium-batterien-etc-series/ncm72ah.html

What's the actual sales price of this square puppy?

 

[Torti]

I want to build a 20S battery and need 20 cells, so I have 72 volts and 72 Ah.



I want to buy a QS 138 engine.




You need to clarify exactly what you “want”..
Why do you “want” 200A ?
200A at from a 72v pack would be 14,000 watts !..
.......and need about 60 of those 72Ah cells ..(or the 42Ah cells if they are 2C !)....and weigh 80+kg
BUT...5000 Watts would only need 20 of hte 72Ah cells ! Running at 72A ! At a more “reasonable” 25kg .
So ,... review your needs , 72v ?...200A ?, ..5000W ?..
[/quote]

 

[john61ct]

Does anyone have experience with these cells?

I found a manufacturer in Germany that can supply a 72AH cell

Again, please link to the **specific** cells you are considering, especially those you think made in Germany.

Showing a CAD drawing which matches cells made by a gazillion cheap Chinese makers does not even get you started on getting good advice.

 

[Pajda]

What's the actual sales price of this square puppy?

check this store: https://lithiumsystem.ch/produkt-kategorie/lithium-ionen-cells/ncm-en/?lang=en I was ordering from antoher chinese producer for about 60 USD per 50Ah cell in small volume of 10 cells including shipping costs. You can get great discount when ordering more than 100 cells.

 

[Pajda]

Great stuff Pajda. Have you got any info on reliable makers of quality LFP in that form factor? I realize energy density will be lower.

Actually I am not sure if I ever see LFP chemistry in this particular format. But it is because I am not interested in LFP at least till the LFMP cells with at least 400 Wh/l come to the retail market.

I got good references from Pedro Lima to this aliexpress stores:

NMC 50Ah
https://www.aliexpress.com/item/4000042651064.html?aff_platform=portals-tool&sk=_dXBfKnU&aff_trace_key=3847643ddf714f78bcc99101c2665da8-1590091455555-02462-_dXBfKnU&terminal_id=9e78c1ab663e44559fe6ca46c024f75f&tmLog=new_Detail&aff_request_id=3847643ddf714f78bcc99101c2665da8-1590091455555-02462-_dXBfKnU

LFP 90Ah
https://www.aliexpress.com/item/4000805306784.html?aff_platform=portals-tool&sk=_dZs6BG6&aff_trace_key=9f110fa888a2412b90f1f1a4f39864ee-1590091623271-02186-_dZs6BG6&terminal_id=9e78c1ab663e44559fe6ca46c024f75f&tmLog=new_Detail&aff_request_id=9f110fa888a2412b90f1f1a4f39864ee-1590091623271-02186-_dZs6BG6

 

[john61ct]

LFP 90Ah
https://www.aliexpress.com/item/4000805306784.html

Excellent

Varicore / Liitokala don't have the rep of say Winston, CALB, GBS or Sinopoly but

that's like half the price, plus free shipping ????

 

[Hillhater]

I want to build a 20S battery and need 20 cells, so I have 72 volts and 72 Ah.

OK.. i realise we are losing some detail with language and translation..where are you based ?
But please understand That a 20cell , 72v , 72Ah pack of these cells , cannot supply 200Amps continuous. !
But it will supply 72A for a 5000W drive motor.

 

[Pajda]

LFP 90Ah
https://www.aliexpress.com/item/4000805306784.html

Excellent

Varicore / Liitokala don't have the rep of say Winston, CALB, GBS or Sinopoly but

that's like half the price, plus free shipping ????

I agree but for that price it is worth of buying sample and run own test. I done this with NMC 50Ah cells from other "noname" manufacturer and it works excellent. Then if you are able to buy higher amount like 100 cells or more(which is still not that much) you will find that you are very close to the price per kWh of small cylindrical cells. Where the volumetric energy density of this particular NMC 50Ah prismatic cells in not that bad and this forced you to think about them.

By the way latest generation of big prismatic and pouch cells (already in mass production) is atacking 600Wh/l and 225Wh/kg energy density. So it starts matching honeycomb layout module energy density with the best 18650 with 750Wh/l and 250Wh/kg per cell. So maybe in next few years, when those cells will be available for DIYers we will leave the small cylinder format.

 

[john61ct]

Yes talking say over 5kWh, IMO crazy to deal with the round cells, greatly prefer hard-cased prismatics.

And I prefer LFP for safety, where density is not so critical, still 3x better than Pb.

 

[john61ct]

By the way latest generation of big prismatic and pouch cells (already in mass production) is atacking 600Wh/l and 225Wh/kg energy density

Pajda, do you still stand by this?

"HP cells have significantly worse cycle life than most HE cells under low loads up to ca 1-2C continuous discharge. Generally(Although I do not like generalizations) HP cells cycle life is almost independent of the load. That means that HP cells should be used only in applications which really needs HP cells."


If so, what do you think of this scenario / question?

https://www.rcgroups.com/forums/showthread.php?p=44573093

Followed up here: https://www.rcgroups.com/forums/showthread.php?p=44582617

Those guys **hate** me bringing up cases under true 50-60C rates!

 

[Pajda]

Pajda, do you still stand by this?

"HP cells have significantly worse cycle life than most HE cells under low loads up to ca 1-2C continuous discharge. Generally(Although I do not like generalizations) HP cells cycle life is almost independent of the load. That means that HP cells should be used only in applications which really needs HP cells."


If so, what do you think of this scenario / question?

https://www.rcgroups.com/forums/showthread.php?p=44573093

Followed up here: https://www.rcgroups.com/forums/showthread.php?p=44582617

Those guys **hate** me bringing up cases under true 50-60C rates!

Yes, it was a bold statement but I think it was usefull for the ES community (mostly traction apps). We can see that docware`s test results are consistent with this statement for many popular cells. Maybe better statement will be that "DCIR value itself does not ensure better service life". But this does not deny that we can find cell with low DCIR and excellent service life.

The discussion on rcgroups is specific that they are comparing samples of cells from "HP" category only. So internal desing of all compared cells is aimed for extra low DCIR and so it is possible that cells with lower DCIR are also using better technology and in generel can have better cycle life as well. My statement was aimed on comparison between "HP" vs "HE" cell category. So I am quite sure that if I compare service life of a good quality BEV pouch HE cell (for example LG Chem with 1C continuous) with good quality RC pouch "Lipo" with 50C continuous, the HE cell will show significantly better service life at 1C continuos.

 

[john61ct]

But this does not deny that we can find cell with low DCIR and excellent service life.

Sure but those are rarely good **value** IMO if you don't need to pay for the power capacity.

> My statement was aimed on comparison between "HP" vs "HE" cell category.

Seems no one cares enough to do low-C testing for longevity on HE cells / packs.

> So I am quite sure that if I compare service life of a good quality BEV pouch HE cell (for example LG Chem with 1C continuous) with good quality RC pouch "Lipo" with 50C continuous, the HE cell will show significantly better service life at 1C continuos.

Yes me too. But when the cells required to be the cylindrical "cans" I don't know of EV quality HE examples.

And the convenience of the hobby 6S packs for assembling short vs long range on different days

or even using them for multiple bikes, maybe 12S for one, 18S for another

is very attractive to me.

In any case, the specific posts I linked to, could you maybe advise? won't hold you to it, just off the cuff guesstimate would be greatly appreciated.