Where to get the best CATL 202ah & 271ah cells for small 4S project?

the evil stepson

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I'm looking to build an expensive portable battery system for outdooring, backup for power outages etc. And won't the best grade & matched cells as it makes no sense spending 1000's on the system then cheaping out on the battery. The CATL 202 & 271 look very attractive because of their high wh/kg.

But I have no experience buying anything like lfp cells from aliexpress & alibaba etc. I can't find these from a reputable distributor by the looks.
Here is what I found from the green store:

Don't these seem quite cheap? Has anyone had success getting grade A well matched through these stores?

There is some confusion for me, according to the evlithium website page they seem to say these cells are rated to 3500cycles to 80% at 1C charge/discharge with their 12V battery, the datasheet for the 202 on this forums says 0.5C, yet on the aliexpress page specs it seems to say they are rated at just 0.2C, does this sound right? 0.2C seems quite low, I think many other brands are 0.3-0.4C.

Basically need hep finding the best cells I can get. thanks
 

Frank in Thailand

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Loads of questions in one post.

The 2500-3500-5000 cycles story.
If you buy and just use, optimal you get 2500 cycles in optimal conditions.

If you compress the cells, so they can't expand /delaminate aka bloating, that should give 1000 extra (again optimal)

Where lead acid loves to be fully charged, LiFePO4 does NOT!!
85-95% max makes it most happy.

Where you can't fully use lead acid (best to stay above 60%) LiFePO4 likes you to stay above 10%

If you use 10-90%, optimal you get 5000 cycles.

Big word here is optimal.
No real life is optimal, and most users are happy to get 2500 after compression and 10-90%.

General LiFePO4 information, regards brand.

You won't find A grade cells online.
Not if you buy less then 1000 cells.

"a grade" for sure :)

A few months back I made a post about ordering LiFePO4 cells.
Please do read, include the "manual" written by @ghostwriter66

Does it make sense to buy for 800 USD today, and again (600?) in 5 years?
(Where with good installation it might last 10 years)

Or buy for $4000 today and again on 10 years?
Where there is no "guarantee" it will last 10 years.

Batttleborn seem to give 10 years.
They do standard the 10-90% and compression.
No DIY, and tripple (or *5) the price of DIY.

The cells that ar used are probably the same you can buy.

Unless you are electric bus manufacturer... Forget it.
You won't get the best.

If you don't mind spending, go with batttleborn or similar product.

If you want to spend less, DIY is a good option and you are on the right forum to learn a lot!
 

Dzl

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CATL cells (to the best of my knowledge) are not officially sold through any retail channels. You can get them on the grey market (where B, C, and A grade cells are not easy to distinguish), but they are pretty scarce compared to some others.

If you are seeking "the best" grey market CATL cells are not your best option.

My 2c, based on the priorities you mentioned (1) grade A (2) matched (3) quality, look at the brands that do sell directly to consumers or have authorized channels (there are many, CALB, Frey/Fortune, EVE, Winston) and buy through one of those authorized channels or direct from the manufacturer. There are good deals to be had on the grey market, but much much more variable quality, and many many B and some C grade cells.

I think Frey/Fortune are a good option if for a portable pack if you are looking for quality. You can buy either directly from the manufacturer or from US or EU based sellers. The cells strike a good balance between energy density and robust construction (I image both would be important for a portable pack). They are also a conveniently thin size which may be beneficial for lugging them around.

CALB and Winston cells are very robust but not very compact. Because both of these companies have authorized retail channels it is not difficult to get grade A matched cells.

EVE cells would require more external protection than the other options probably, but have the best energy density of the options I listed. B grade EVE was very popular on AliB and AliX for a while, much of it was B grade, probably none of it was well matched (unless you buy from EVE directly--which you can, (and should if you go this route) if grade A matched cells are your top priority).
 

Steve_S

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BE AWARE, that Vendors use the Term "MATCHED" very loosely and it is often NOT what you think it is.
Properly Matched, Batched cells cost more, it is a long & tedious process (even automated).

There are ESS, EV & other gradings & classifications for cells. These are Different and should not be confused, unfortunately, many vendors are far from clear on these points as well.

When cells are capable of 3C or even 5C rates, they are of better quality materials and much higher tolerances than those which are limited to 1C Rate max. EV Grade level cells typically have much higher C-Rates.

Properly Matched cells, such as those used by Battleborn cost more from the outset. This of course increases the product cost but provides for use of the full voltage curve and maintains internal IR throughout the operating range, which prevents "runner" cells.

The Commodity Cells (ie 280AH for $80 USD +/-) are NOT matched by any means. They are still Grade-A ESS but bulk & untested (unqualified). They will operate within the standard 3.4-3.1 LFP curve but will have runner's above & below those voltage ranges limiting "full" use of cells. NOTE that above 3.5 and below 3.0 only represents about 12% of actual capacity which generally people block from using to maximize lifecycle.

Good Luck
 

JoeHam

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And unfortunately I don’t have an answer for the original question about a good source for CATL.

The overwhelming volume of discussions on the forum are about EVE and Lishen.
 

Frank in Thailand

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And unfortunately I don’t have an answer for the original question about a good source for CATL.

The overwhelming volume of discussions on the forum are about EVE and Lishen.
IMHO you received a really good answer, just not the one you liked.

You can't buy grade A CATL, unless high volume.

All other sellers that sell CATL (what you seem to have your mind set to) will sell a golden wrap on Grade B/C and call it Grade A.

Mind you, Grade B/C today would have been Grade A a few years ago.
As technology advances, so do the grade scales.

I have to disagree with @Dzl

The Alibaba link is just one other reseller, who "claimed" the name.
Eve doesn't provide in any official site a link to "their" Alibaba shop.

It can be it's newly opened, since s few months.
If not, it's an other gold wrap :)

The other links, great find!
Perhaps @Will Prowse can make sticky?
 

Dzl

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I have to disagree with @Dzl

The Alibaba link is just one other reseller, who "claimed" the name.
Eve doesn't provide in any official site a link to "their" Alibaba shop.

It can be it's newly opened, since s few months.
If not, it's an other gold wrap :)
I appreciate your skepticism.

And I won't pretend I can 100% say you are wrong. I've seen enough convincing fraud and deception in this area to know to always be a little skeptical and a little wary of anything that can't be proven or evidenced. I will look into this.

The other links, great find!
Perhaps @Will Prowse can make sticky?
Personally, I don't think this is a good idea. Anything that looks like official endorsement or promotion of certain sellers would have some value but would probably cause more trouble for the forum (and invite more marketing, and salespeople, and influencers, and spam to the site) and also give the impression of endorsed or vetted sellers. I do think a thread or resource devoted to this might be beneficial to everyone, just not official or authoritative.

There are many good sellers and many bad sellers and many in between. I personally don't endorse any of the ones I linked to above or any other sellers really. But I do think all of the above are more suitable options (if your priority is quality) compared with buying from grey market resellers, particularly just a random aliexpress seller. The likelihood of Grade B is very high (which for many people is acceptable for the cost). If your priority is cost, the grey market sellers are a reasonable route to take if you understand the trade-offs.
 
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Dzl

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I appreciate your skepticism.

And I won't pretend I can 100% say you are wrong. I've seen enough convincing fraud and deception in this area to know to always be a little skeptical and a little wary of anything that can't be proven or evidenced. I will look into this.
Okay, circling back to this:
I have to disagree with @Dzl

The Alibaba link is just one other reseller, who "claimed" the name.
Eve doesn't provide in any official site a link to "their" Alibaba shop.
I have done a bit of digging and now have moderate confidence that this is EVE's official Alibaba storefront.

You can view the 3rd party verification for the storefront (verification overview, verification full report) It should be noted, third party verification just shifts trust to a third party, and is only as good as the third party is trustworthy and thorough. I know nothing of this companies reputation, but they did complete a detailed verification and inspection at an address that is registered to EVE proper. They (TUV Rheineland) appear to be the largest technical certification and compliance company in Germany.

The third party report was prepared for "Eve Energy Co., Ltd." and the EVE official website references "Eve Energy Co., Ltd."

The report lists the same address that is listed on the official EVE website, and has done an onsite inspection of the premises (documented in the report, including pictures of the facility and certifications and documentation--which I have not verified).

The Chairman of EVE (according to their website) is Dr. Liu Jincheng, this is also the 'corporate representative' registered in the 3rd party verification.

Is verified to be a manufacturer and trading company, and a public company with over 3000 employees.

I do not know how much trust to place in the third party verification, but at the moment, my assessment is 'more than none but less than full' :)
 
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Frank in Thailand

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Okay, circling back to this:

I have done a bit of digging and now have moderate confidence that this is EVE's official Alibaba storefront.

You can view the 3rd party verification for the storefront (verification overview, verification full report) It should be noted, third party verification just shifts trust to a third party, and is only as good as the third party is trustworthy and thorough. I know nothing of this companies reputation, but they did complete a detailed verification and inspection at an address that is registered to EVE proper. They (TUV Rheineland) appear to be the largest technical certification and compliance company in Germany.

The third party report was prepared for "Eve Energy Co., Ltd." and the EVE official website references "Eve Energy Co., Ltd."

The report lists the same address that is listed on the official EVE website, and has done an onsite inspection of the premises (documented in the report, including pictures of the facility and certifications and documentation--which I have not verified).

The Chairman of EVE (according to their website) is Dr. Liu Jincheng, this is also the 'corporate representative' registered in the 3rd party verification.

Is verified to be a manufacturer and trading company, and a public company with over 3000 employees.

I do not know how much trust to place in the third party verification, but at the moment, my assessment is 'more than none but less than full' :)

After looking into your "evidence", I have to agree it's likely EVE started own channel of sales for "gray" cells.
That is actually good news!

You have bigger chance to get Grade B there, not Grade C (or D)

Talking about Grades, I still haven't found any "official" qualifications that would make a cell be grade A or B.

It's "known" information grade A is "better" then grade B.
But how exactly?

You are right that it can not be an official sticky.
I've spent quite some time with a lot of different LiFePO4 sellers to "know" the bad ones from the good ones.
In this light I do need to write that it's "normal" in China to build a good reputation and then "cash it in" by providing low quality products.
Sure, that gives them a bad name, also huge profits. And probably they own more then one store...
That's a side step.

As long as the stores don't do this, I made a post a while ago with sellers I have used or heard good experience from, via buyers I know who know what to expect with Chinese sellers. (Link a few posts back)

That's probably the best way to do it, having users like me provide the information.

From that list, Donguang (or so) might be in the time of "cashing in".
Not yet confirmed but they might have send out a set of Lishen 272 instead of EVE 280.
At $13 extra per cell... Nice profit ☺️
If confirmed, sure they will be removed.

OP see a lot of post about Lishen and EVE, as those are available at this moment.
6 months ago "no one" ever heard of Lishen.
12 months ago "no one" about EVE.
I need to search the old threads to see what was "hot" September 2019..

Brands come and go on Alibaba.
Perfect place for the factories to sell a batch go slightly wrong, or overstock.
As they don't want the hassle, it's without factory warranty, gray market.
And as many of us know, that doesn't mean they are bad.
Really good even!

For price and quality in LiFePO4 Alibaba probably is the best place to be.
Mission critical components..
No!
Batttleborn probably use the same cells we do, but provide kickass warranty and they way it's made, easy to swap a box who went bad.
You pay for this warranty and ease.
Cell quality wise... The same.(or close enough)

Going the DIY route with LiFePO4 after spending thousands of dollars on equipment sounds to me Penny wise, Pound foolish.
Unless that equipment was DIY also and the parts are just that expensive... Match the wallet with the usage.
There are some better products out there, 10.000 cycles standard like Lithium Titanate.
No "Grade-A" LiFePO4 could even come close to that lifecycle.

Is lifecycle the only measurement in grading?

Energy density?
Lithium nickel cobalt aluminum oxide battery, or NCA, with Specific energy (capacity) 200-300Wh/kg..

Trade offs, always :)

What ever type you desission will be, Alibaba will give you reasonable quality for a good price without factory warranty.

If you need that last one, batttleborn, BYD or other brand with long and good reputation.
 

the evil stepson

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Holy Cow!!!

Big thanks to fhorst, Dzl, & Steve_S.
That is some serious good advice & set me straight, or brought me back down to reality.
I will spend some time looking at those links, but sounds like I just have to accept the grey market quality.
 

the evil stepson

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Going the DIY route with LiFePO4 after spending thousands of dollars on equipment sounds to me Penny wise, Pound foolish.
Unless that equipment was DIY also and the parts are just that expensive... Match the wallet with the usage.
There are some better products out there, 10.000 cycles standard like Lithium Titanate.
No "Grade-A" LiFePO4 could even come close to that lifecycle.

Is lifecycle the only measurement in grading?

Energy density?
Lithium nickel cobalt aluminum oxide battery, or NCA, with Specific energy (capacity) 200-300Wh/kg..
I'm building a very compact portable power station that will weigh total 45-50kg & my goal is for it to have a very long service life. Using as example two shore power chargers for some serious punch, each one costs me 1000AUD. Twin dc-dc charger, victron 3000watt inverter, hundreds of dollars alone on wire, crimps, switches etc. A complete rats nest of wiring. The cost rises really fast, but when you see it support a family of 4 people in the middle of the desert then I know to my self it's worth every cent.
I use common parts that can be ordered online & replaced in 5mins, To me DIY lifepo4 is the only way to go, especially with the high density.

I have thought about NCA but no charger can charge to those voltages & I would need a step down converter as the fridges, lights etc don't like 16V+
LTO is about the same specific energy as lead acid last I looked so that is not possible. I think those 10,000cycles would not be well matched to the victron 5year warranty.

all the best.
 

Frank in Thailand

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Seeing it support family of 4, I do daily :)
Sometimes 5 or 6.
No desert but Isaan Thailand.
During dry season it might as well be called desert!

Battery is one part, solar the next.

In the desert you probably don't have rain season with much cloud cover

I based our panels on that period, 27* 330 & 16* 340 watt.
That is not mobile :)
Same for the LiFePO4 setup, 50 kWh.

Money goes fast.
Our deep well pump alone likes 2000 watt, peak 3000 to start.

It might as well be desert, we didn't have rain for 6 weeks, all days +30.
In February/March hot season, +40 on regular basis.

Then I'm happy with our air-conditioning units!!

It did need additional pre-cooling as the location of the outside units quick rise to a level where cooling become an issue.

Lucky, water vaporise and a misting system in front of the air intake pre-cools the air.

It starts automatical at +38
Or.. should start.
Installed it after the hot season, and we didn't have that temperature yet.

I went from 32x 152 to now 32* 280 + 48* 152.
One always uses more power then you first anticipate.
Especially if you like some comfort like air-conditioning, or deep well pump, with all the needed equipment to clean that water.

Besides that, garden, pond and working on aquaphontics /hydrophonic system...

Energy goes fast.

LiFePO4 is the good middle road.
BMS is needed equipment.

I used to say Daly is good, and they probably still are.
Just not at the +100 A models smart and not smart.

I started out with active balancer BMS, that worked great for 3 days.
To early launched.
Now they are good.
From there to 2 high end Daly (dead) to now DIYBMS (in progress)

I'm not in a hurry as I monitor my cells with the active balancer (without BMS part) and that works good.
My inverters stop on time and the active Balancer keeps the cells balanced.

Still...
It would be ease of mind to have BMS in place to stop charge or discharge if things get crazy.

My requirements where 32*152Ah.
That is, if I could use them 80%.
On a normal day.

Fact is, there are no normal days.
Well pump may start at a time the sun isn't powerful enough to provide its energy.
And at higher temperatures my energy efficient Samsun Inverter refrigerator suddenly isn't that efficient.

Even 48*152 didn't cover my needs if there was a few days overcast.

To make sure I won't have issues, I got 16* 340w panels and 32*280 LiFePO4 extra.

Now we have enough.
Even enough to power my crypto mining rig.
(It uses +/- 750 watt and makes 3 to $10 a day)
On average 100-150 per month :)
Poetic, solar mining..

For you, 50kg max for the whole setup.
Where one 280Ah is already 5.5kg..
If it's maximal 50 kg, I would say it's for hiking or biking.
Car/RV it's not so quickly an issue.

Hiking/biking aka camping, one doesn't need that much power.
Not even close to 2500 watt!

Just curious, why heavy inverter where probably 300 watt would be sufficient?
The 3000 watt will have like 60-80 watt own consumption, always.
Where a 300 watt would be 15-20...
That is continue usage, just for turning on the inverter.
 
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Dzl

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I appreciate your skepticism.

And I won't pretend I can 100% say you are wrong. I've seen enough convincing fraud and deception in this area to know to always be a little skeptical and a little wary of anything that can't be proven or evidenced. I will look into this.
Okay, I can now say with 100% certainty that the EVE website and EVE alibaba page are the same company. I reached out to EVE through the email listed on their website. They confirmed that the Alibaba store: evebatteryglobal.en.alibaba.com is the official (and only official) sales channel they sell through on Alibaba.

Unfortunately I also have to report it may not be a convenient or practical sales channel for small buyers. (1) shipping terms are FOB only (2) With the new model LF280N it is designed to be laser welded, so terminals are not tapped and busbars/screws not sold with them. This may or may not apply to smaller cells.
 

Frank in Thailand

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Thank you.
I googled a little on welding options for this type of cells.
There currently isn't a cheap solution available :-(

Cheap as in "do I want to spend $20.000 on laser welding equipment" where $20.000 for laser welding equipment is entry point, so.. actually cheap :)
 
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