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LTO "Grade A" Aliexpress Cells

This is why I developed a system to test every cell before I sell them on ebay. Grade A is Chinese for they look pretty. After testing over 1000 cells I have found 2 suppliers that actually sell full capacity cells as advertised
What is the approx cost per Ah or cost per kWh for these suppliers. How does it compare to the others.
 
Quick update: The BLS store is giving me a full refund for the issues I experienced with their LTO cells.

They said that they made a mistake and the cells were not labeled correctly.

They wanted me to remove the video, and I refused. I told them that this will be a lesson to ensure that it never happens again.

I still do not understand why these problems happen so often with battery distributors. This has happened on numerous occasions w/ multiple suppliers. Hopefully my video will teach the other companies a lesson.

Previously, I did like the BLS store, and I have bought some really nice cells from them in the past.

I am glad that I was ripped off before my viewers were. Who knows how many people they sent these cells to. If you bought these cells, test them and return them if necessary.
 
Hello,

I want to share my YinLong LTO cells experiences here since I might be useful to anyone:

1) First it is important to know that Yinlong is owned by BYD which is an electrial vehicle producer. BYD is the one of biggest electric vehicle company world-wide beside Tesla. This year Tesla could sell more vehicles, but until 2019 BYD was world-wide #1 producer.

2) All Yinlong cells are used. No "brand new" cells exists! All new Yinlong cells are used for multiple years (up to 10 years) within electric vehicles like buses. Since the high c-rate of 10C you can load for example buses quickly at (end-)stations. Also, break/acceleration power of the buses is put on the LTO cells. From my opinion and what I have researched, you will never get/buy a complete new LTO cell from Yinlong. But for solar storage you do not need 10C at all. Please notice, I never was able to do a 10C test, but I do see my LTO cells have a higher impedance, but this is not a problem for me at all. Image of one aliexpress seller:
lto5.jpg

3) Once the impedance of the LTO cells within the electric vehicles are getting to high, the cells are removed from the electric vehicles and get rewrapped with the blue heatshrink design we know from Yinlong LTO cell. Under the heatshrink - and while used in electric vehicles - the cells looks as follows (images not from myself, found on the net):
lto2.jpglto3.jpg

4) The capacity and impedance of the used cells is checked and this results how the are labelled/wrapped. Therefore, we do have 30/35/40/45 ah in 66160 format. By the way, within the past Yinlong also produced 55ah LTO cells in 66260 format, but they are not build anymore. We do have different cell grades: A/A-/B/C. Once a seller have posted an image about the cell grade for 40ah cells:
OIP5HZY5P8A.jpg
I can confirm on my orders (40ah only) on aliexpress, the cells are categorized with this parameters.

5) If built a 6s5p bank and have ordered 36 LTO cells at aliexpress. I have done three different orders to different times. From my experience I have gotten the most weak cells on special actions like "Single days" or "Black Friday" sales. Usually, you buy packs of 6 cells (6,12,18,24,30,36, etc) and from my experiences so far (get a lot more cells the next days...): From 6 cells, 5 cells are as promised (for example over 40ah) and at least 1 cells is way too low. I have checked/tested every single cell and listed them as follows:

ltocells1.png
ltocells2.png

The first order (#1-#12) was not on a sale and they are pretty average. The second order (#13-#24) was a "Black Friday" sale on the cells are bad quality (4 cells below 40ah). Then I complained about the cells and the seller send me the third order (#25-#36) for the halve price. While other orders are mixed in cell grades, the third order was all "Grade A" cells.

Capacity test parameters: Load to 2,6V, Cuttof at 0,5A - Unload to 1,9V, 8 Ampere discharge / This means there is some little unleft capacity which should not matter.

6) The weight of each cell is important, BUT also light weight cells can offer the capacity. I do think, they sellers at aliexpress do not know much about the cell quality they are selling. I do think the packs are packed by weight. My packs of 6 cells are all 7,175kg and 7,295kg - no matter which grade. Additionally, I do not think the sellers have the time to test the capacity of each cell there are selling. But I must add, that one ordered box someone noted by hand ">38"...

7) The cells can be balanced all ways. I have bottom-balance them, top-balance them and they are quite stable. However, due the different impedance of each cell, over (long time) they will drift. From my experience the cell drift is small, even due the different impedances. Currently, I am using an QBBM active balancer and I am quite happy with it, just works.

8) Discharge efficiency is good! Nothing to worry about. Also self-discharge is nothing to worry about.

9) The cells are very robust. I have revived cells with 0,5V or lower with full capacity. They are working on my bank as this never happens. They are happy within a very wide temperature range.

10) My usage range of these cells is between 2,0V - 2,5V. It is possible to use a higher range, but this works very stable and accurate for me and I got more than 85% of the capacity.

11) One of the most annoying things are the aluminium screw threads. Be aware if you use any sort of loctite, it might be possible you will never ever getting be able to untighten the screw anymore. Even without loctite etc., some you will destroy the screw thread on thighting. I have lost one cell since I was not be able to remove the screw anymore.

12) You can build quite cool - no amazing battery packs with Yinlong LTO cells - but from my opinion you need to check every single cells capacity and loading behavior. I can remember a cell which was really hard used and have bumpy charge/discharge curves, instead of the usual smooth ones.

13) Never buy cells from GTK manufacturer. While I never ordered ones, there capacity seems all to be lower as promised. Also, they are way cheaper then Yinlong cells. I would advice to avoid them!

14) I do not have evidences that the cells are all used. Surely, no one will tell you this, every seller only sell "brand new" Grade A++ cells. But it seems so obvious that these cells are used and rewrapped!

15) I do like them, I am really happy with them. Works perfectly for me on 12V, as on 24V. While this only based on my own opinion I hope this information is helpful for anyone!

Bye
Tobi
 
Interesting if it is true those cell are used like all hell. But still are usable for us.
If they are all used .... seems like they should be able to sell them a lot cheaper than they are. Maybe they figure they have such longevity that they can get away with it.

@Craig .... What is your experience with the IR on these cells? Can you tell from an IR check how they are going to perform?
 
If they are all used .... seems like they should be able to sell them a lot cheaper than they are. Maybe they figure they have such longevity that they can get away with it.
Isn't that the truth. I guess it is possible that these cells or any of the cells could be used but still look new. They could be protected in an enclosure and never touched for years.

These ideas have made me more suspicious of all of the cells including the EVE cells we all are using. Most of the terminals on the cells we get have marks on them. But any cell manufacturer would be sure those terminals were protected.

I'm not claiming to have figured anything out but thoughts are bouncing around in my head.
 
These ideas have made me more suspicious of all of the cells including the EVE cells we all are using. Most of the terminals on the cells we get have marks on them. But any cell manufacturer would be sure those terminals were protected.
I think suspicion/skepticism is a good default approach in this context. When I first joined the forum this was the norm, and due diligence and skepticism was passed on to new folks like myself. But over time that spirit has been watered down more and more, most notably with the explosion of new users joining to get in on the cheap EVE cells.

Personally I feel that over the past 8 months or so, we have lost a lot of that caution, and as a group our expectations have become less and less realistic. And we have fallen into the trap of 'believing what we want to be true' rather than accepting and acknowledging the uncertainty and ubiquity of B grade cells (being sold at B grade prices). Now its entirely possible that some number of people will get A grade cells at discount prices for any number of reasons (overstock, old model, etc), but its more likely that the B grade price = a B grade cell more times than not. And the reason for the discount is because they are a lower grade of cell sold without warranty, support, or guarantee of quality, that cannot be sold to commercial customers. This can still be a great value, but I think we need to be realistic.
 
Wonder if anyone in the forum actually get the real grade A 45AH cells before? There is a lot different generation of Yinlong LTO cells out there.
45AH <= 1.25kg
40AH <= 1.22kg
 
If they are all used .... seems like they should be able to sell them a lot cheaper than they are. Maybe they figure they have such longevity that they can get away with it.

@Craig .... What is your experience with the IR on these cells? Can you tell from an IR check how they are going to perform?
Usually the bad ones have a low voltage when I pull them out of the box for testing this is not a completely accurate test though but about 80% effective. Yes I think all of these cells are used but still have plenty of life left for solar. I have my home setup going now for about 5 months without even looking at it. This runs my garage only and a chest freezer not the whole house. My Idaho cabin setup has been going since April without issue as well.
 
Yes I think all of these cells are used but still have plenty of life left for solar.

66% left if you believe the picture. I'm not sure what to believe.
For my purposes it probably won't make any difference but I doubt you can expect to get 10 years of heavy use out of used EVEs.
 
66% left if you believe the picture. I'm not sure what to believe.
For my purposes it probably won't make any difference but I doubt you can expect to get 10 years of heavy use out of used EVEs.
I am not convinced the EVE's are used. Where would that many used EVE cells come from? I would think thousands have been sold. Also used cells usually have the label scratched off or altered. And even the ones that have tested at 265ah's have 95% capacity. It seems kinda strange to me we bought used cells. But I don't know any more than you do about where these cells are actually coming from. I suspect they are simply factory rejects good enough to sell on the grey market. All of mine have been marked with a black magic marker....whatever that means.

A couple of my cells had marks on the terminals. Could that have been from some random testing being done by EVE, the supplier or both? We will probably never know any of this and all we can do is speculate. But it is an interesting discussion even if filled with speculation.
The only thing we do know for a fact is that these EVE's are not Grade A cells.
 
Will : Granted you probably got 35ah re wrapped cells , But I thought AH tests should be done at 1C.

The doubling up on the buss bars isn't a good idea , Because of aluminum anodizing is an oxide and adds to the resistance , Its better to use a one thicker bar.

Also I do not trust anybody Aliexpress , They are like an Ebay, I use Alibaba with Osn and Kokpower , I have received what I ordered to spects.
 
Will : Granted you probably got 35ah re wrapped cells , But I thought AH tests should be done at 1C.

The doubling up on the buss bars isn't a good idea , Because of aluminum anodizing is an oxide and adds to the resistance , Its better to use a one thicker bar.

Also I do not trust anybody Aliexpress , They are like an Ebay, I use Alibaba with Osn and Kokpower , I have received what I ordered to spects.
What makes you trust OSN or Kokpower? Or maybe a better question, how did you first come to trust them before you had experience with them?
 
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