Are we all getting GRADE B cells??

[robby]

I feel a little skeptical of SFK. They were initially doing their tests wrong and stated that they were not with very high confidence. They also have financial incentive to bash other sellers. It's interesting data nonetheless

You must have a crystal ball because look at all of the info we have learned since you made that post.

 

[Hipster]

The Standard Amy Wan (Shenzhen Luyuan) Spiel on cell grades goes like:

About the 280AH, we have two grades to choose from (both are the new version LF280K, brand new):
Grade A: fully matched, with the test data from the original factory. Its price has risen a lot, the newest price is $190/pcs.
Grade A- : Its internal resistance and voltage are matched, the capacity is not. We tested the real capacity of some cells,at 275-284AH. $111/pcs.

When EVE tests grade A cells, if some ones do not meet the specification (for example, the capacity is insufficient or there are some tiny defects in appearance), they will pick them out. These cells are A- I mentioned.
Many other sellers claim that it's grade A, but in fact, it's not.

I suggest grade A and full matched more, but its price is already very high, if you plan to use them in a solar system, grade A- is also an option.

I ordered A- (minus), I really don't care if I lose a small percentage of capacity.
I mean, almost half price, for the difference, I can assemble another battery, I'm almost certain to gain in capacity, am I not?
It's not as if I'm making it for someone else, and I never discharge past 50% with the much smaller ones I have anyway.
-

how can i get in touch with this Luyuan for cells ?

 

[Don B. Cilly]

Chat on Alibaba is probably the best option.
Try https://szluyuan.en.alibaba.com and use Chat Now.
-

 

[Alkaline]

As someone who has luyuan cells and posted tests with a ZKE-40 I would suggest you not buy LF280K grade A or B and instead buy 304 Cells. here are my results:

https://diysolarforum.com/threads/what-is-going-on-here-just-got-zke-40.49076/#post-624032 278AH & 901 WH

so averaging 276-278 with only 1 cell around 280

Based on this I conclude unlike the Original 280N or the 304 the 280K is a poor design that does not pull capacity in AH, and barely make the WH rating.

Full Disclosure: Amy Wan says these cells are fine and now generally never even responds to my chat requests saying my equipment is not professional... I also talked with Lampard Li from EVE and he said the same thing your equipment is not professional...

Its because of this reason I have decided not to ever fool with DIY again, for me 3 strikes its out, First it was Xuba, then Basen and Now Luyuan.

I will say aside from the capacity problem the Luyuan Cells work well don't do anything funny and hold voltage underload better than the Basen or Xuba cells so good, but no My sheet that I got said these were between 285-288. The manufacturing date was January 2022.

Xuba cells were the worst me for me, followed by Basen, and Luyuan were Ok, but overpriced for what was delivered.

That being said apparently grade B 280K are just as the Docan cells are 263 AH with less than 795 WH rating, with the Luyuan Cells at least they were all around 899-903 WH.

 

[koobs]

What equipment were you using?
The grade A cells I got from shenzen luyuan all tested pretty much what their spec sheet said.
The grade B cells i bought off her, she said 280 to 274. And yep all within those ranges too.

All the cells Ive bought, I have done 200A discharge tests for 5min, and all show pretty low voltage drop under such large loads. Well within A grade specs

As someone who has luyuan cells and posted tests with a ZKE-40 I would suggest you not buy LF280K grade A or B and instead buy 304 Cells. here are my results:
.....

 

[Alkaline]

ZKE-40 its the same tester Andy from Offgrid garage uses, I uploaded my picture and also csv data:
check this thread: https://diysolarforum.com/threads/what-is-going-on-here-just-got-zke-40.49076/#post-624032

BTW I'm not the only one, I think anyone that bought 280K made from November 2021 to January 2022 are getting similar results.

Just my Luck I buy the perfect time to get the worst of the grade A.

I also checked 18650batterystore.com, and look at there reviews, people saying the same 277Ah using a ZKE-20 tester.

EVE LF280K V3 Grade A Cells - 3.2V LiFePO4 280Ah Battery

Brand new Grade A EVE LF280K LiFePO4 cells with 280Ah capacity. 10+ years design life, 6,000 cycles. Get unmatched power and performance for your energy storage needs.

www.18650batterystore.com

 

[koobs]

Hmm interesting. None of mine are in that date range. All are a tad older.
Different tester though. Maybe mine is more generous

 

[Alkaline]

When were your cells made, clearly i'm the unluckiest DIYer on earth ?

 

[koobs]

Ahh just checked and i lied. The grade B shipment I got was indeed all between Dec 2021 and Jan 2022. They tested between 274 to 278, as Amy said they would.

The batch of grade A that I got awhile back were all from July 2021 specifically. They tested fairly above the 280Ah mark, I can't remember but I think most were roughly in line with what their supplied test data sheet said.

In the end I'm not too worried about the exact test capacity of these cells. I've got 48kwh hooked up at home and am averaging 30 to 40% daily cycles. Calendar ageing will probably kill these cells long before anything else.
The 32kwh I've got at the farmhouse does even less daily cycles.

 

[Alkaline]

Did Amy give you a spreadsheet with test results? Are you sure it was grade B? How did you test do you have WH and AH readings..

I'm starting to get pissed now, your grade B are testing like my Grade A...

 

[John Frum]

Why muddy the water with watt hours?
The accepted metric is amp hours.

 

[Alkaline]

I want both and say this after viewing graphs look here:

Poor Docan Experience (Resolved)

Purchased 16 eve 280k from Docan over a month ago confirming the description had them as brand new, full capacity cells. Cells arrived bloated, more than 5mm out of spec at only 3.2v. No grade B QR and had the front labels that they had been "tested" at 280ah and matching IR .19. - Reached out...

diysolarforum.com

Compare Cell1 - 274AH & 880WH vs Cell7 274AH & 866WH

If you look at the AH you would think they are the same, but they are clearly not. Also notice the voltage Cell 1 average voltage is 3.2V and Cell 7 average voltage is 3.16

So I much rather have cell 1 than cell 7 I get 14 more WH. That is like a 25% of a MacBook air battery life.

AH by itself is not good enough in my book, I want both and grade A better pass both AH & WH. The 280K is 896WH and 280AH.

BTW this is what convinced me to get a ZKE-40 tester which I think has been one the best investments I have made in this hobby.

 

[John Frum]

AH by itself is not good enough in my book, I want both and grade A better pass both AH & WH. The 280K is 896WH and 280AH.

Were both watt hours and amp hours explicitly promised in the terms of your deal?
If yes then you may have a beef.
You can want whatever your heart desires but the lingua franca is amp hours.

 

[Just John]

As someone who has luyuan cells and posted tests with a ZKE-40 I would suggest you not buy LF280K grade A or B and instead buy 304 Cells. here are my results:

https://diysolarforum.com/threads/what-is-going-on-here-just-got-zke-40.49076/#post-624032 278AH & 901 WH

so averaging 276-278 with only 1 cell around 280

Based on this I conclude unlike the Original 280N or the 304 the 280K is a poor design that does not pull capacity in AH, and barely make the WH rating.

Full Disclosure: Amy Wan says these cells are fine and now generally never even responds to my chat requests saying my equipment is not professional... I also talked with Lampard Li from EVE and he said the same thing your equipment is not professional...

Its because of this reason I have decided not to ever fool with DIY again, for me 3 strikes its out, First it was Xuba, then Basen and Now Luyuan.

I will say aside from the capacity problem the Luyuan Cells work well don't do anything funny and hold voltage underload better than the Basen or Xuba cells so good, but no My sheet that I got said these were between 285-288. The manufacturing date was January 2022.

Xuba cells were the worst me for me, followed by Basen, and Luyuan were Ok, but overpriced for what was delivered.

That being said apparently grade B 280K are just as the Docan cells are 263 AH with less than 795 WH rating, with the Luyuan Cells at least they were all around 899-903 WH.

I can say every single 304AH I purchased from Amy measured 310AH or above using a ZKE. The 105AH cells all measured above 108AH. I have not ordered the 280AH except about 3 years ago, they all measured between 264 and one at 280 (but also not from Luyuan).

 

[Just John]

ZKE-40 its the same tester Andy from Offgrid garage uses, I uploaded my picture and also csv data:
check this thread: https://diysolarforum.com/threads/what-is-going-on-here-just-got-zke-40.49076/#post-624032

BTW I'm not the only one, I think anyone that bought 280K made from November 2021 to January 2022 are getting similar results.

Just my Luck I buy the perfect time to get the worst of the grade A.

I also checked 18650batterystore.com, and look at there reviews,

people saying the same 277Ah using a ZKE-20 tester.

EVE LF280K V3 Grade A Cells - 3.2V LiFePO4 280Ah Battery

Brand new Grade A EVE LF280K LiFePO4 cells with 280Ah capacity. 10+ years design life, 6,000 cycles. Get unmatched power and performance for your energy storage needs.

www.18650batterystore.com

Yes, I have used the same tester a lot, plus compared results with other designs, even calibrated loads. The ZKE-40 is accurate.

Thread 'Fast/Large capacity cell tester.' https://diysolarforum.com/threads/fast-large-capacity-cell-tester.22105/

 

[koobs]

Did Amy give you a spreadsheet with test results? Are you sure it was grade B? How did you test do you have WH and AH readings..

I'm starting to get pissed now, your grade B are testing like my Grade A...

I got a spreadsheet for the grade A cells. Not the grade B cells.

I used a generic tester, the type you get on aliexpress awhile ago. Here's a pic of it.

 

[augiedoggy]

NEVER EVER PAY WITH BANK TRANSFER TO ANYONE ON ALIBABA. If you do you, then you deserve everything that is coming to you.

The seller knows how you paid, and they have you by the balls if you do bank transfer they can change up your order and do other nonsense send 272 AH instead of 280 e.t.c nothing you can do, if you contact Alibaba they will tell you, Hey work with your seller and figure it out.

But when you pay with credit card and file a charge back alibaba will start crying please please cancel dispute please please save the world and end global hunger by canceling your dispute ?

I think Luyuan is the best Alibaba seller but I would still never pay with a credit card. Some time ago there are people who had there shipment get stuck in UPS warehouse because of a fire, I don't know what happened but I'm pretty sure the rest of the shipment got seized. Luyuan's cells got stuck in this mess. Paid with check, congratulations now you are stuck... Not saying Amy won't do everything to solve the issue, but that is the only recourse you have left.

Lastly, remember all these cells are shipped without the correct markings if they don't have that UN Lion sticker and declaration UPS / FEDEX will deny any damage claim.

So keep that chargeback finger ready and walk away if something doesn't feel right.

BTW I talked with Chase about this and began talking with a rep, while after a long conversation I got this chap to reveal that they basically don't even bother listening to aliexpress and alibaba anymore, like 99% of the disputes for these 2 sites get ruled in the buyers favor because of all the issues. Paypal will tell you the same, I'm sure this one of those problematic sites where the dispute ratio is so out of whack they probably hold alibaba/express funds for 90 days before even releasing it to them.

BUT yeah, NEVER EVER EVER PAY with a bank transfer.

I just want to point out that I agree while paying with another means is ideal, I have a brewery and a few years ago I found the manufacturer that makes the equipment thats rebranded and sold in the US at a 300% markup... anyway I did in fact pay them with a bank transfer (partial payment before partial when shipped and final when received) since thats all they accepted at the time and all was well, in fact Ive ordered additonal equipment from them later doing the same.

 

[justgary]

I'm starting to get pissed now, your grade B are testing like my Grade A...

I got a spreadsheet for the grade A cells. Not the grade B cells.

I used a generic tester, the type you get on aliexpress awhile ago. Here's a pic of it.

You paid for testing and providing a spreadsheet to prove that you bought good cells. You call that Grade A.

You didn't pay for testing and a spreadsheet and took your chances on whether they were good. You call that Grade B.

Nothing there says that the cells are any different. Why expect them to test differently?

 

[Just John]

I'm starting to get pissed now, your grade B are testing like my Grade A...

I got a spreadsheet for the grade A cells. Not the grade B cells.

I used a generic tester, the type you get on aliexpress awhile ago. Here's a pic of it.

I have compared results from this tester with a calibrated lab instrument and found them to be more accurate than I would expect given the price point.

 

[Just John]

BTW this is what convinced me to get a ZKE-40 tester which I think has been one the best investments I have made in this hobby.

I would agree with that.

For anyone interested, here is where I purchased mine:

https://www.aliexpress.us/item/3256801785667407.html