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Review of EVE 280K cells purchased from Shenzhen Oneier Technology Co.,Ltd

What I find weird is that these were supposedly manufacturered on April 15th but still have the old terminals. Mine were manufactured on April 11th and 13th and I have the new terminals.
 
New terminals? The double threaded terminals? I believe those are Eve installed terminals.

For sun grade cells each reseller can toss what terminals on they want.
 
Amazing stuff.

So if my cells were manufactured prior to March 22 then I assume no need to go through this effort, just leave the bar code alone; no way to tell if they were A or B. Now resellers have to go through all this to cover over the B even though we have been buying B grade cells all along. Crazy.

Well at least I know they were recently manufactured and not sitting around for a year. I knew by the price I was not getting A+ (automotive) and these don't look used so most likely cells that EVE sold as B, which is what I expected.

Can anyone elaborate on how this is done and the equipment required.
It would all be highly automated, I'd suspect a batch of data would be sent to the printer and all the cells would be burned with the data using a laser.
A quick duckduckgo search found this https://www.alldotech.com/qr-code-laser-engraving-machine/
I've done a fair amount with regular barcodes streamlining processes at work... You can make a barcode contain pretty much any data you want.
 
New terminals? The double threaded terminals? I believe those are Eve installed terminals.

For sun grade cells each reseller can toss what terminals on they want.
Ahh, gotcha. Did not know this, thanks.
 
"I think you got re-lasered cells."
Alkaline was correct (sharp eyes!). The cells were manufactured in April after EVE started labeling non automotive cells with a B on QR code. This no doubt caused problems for resellers who had marketed these as non automotive A cells. Problems yield solutions, but not always the right ones . I will start testing the cells next week but I am giving Oneier the benefit of the doubt for now that I received what I paid for; New, unused 280AH (=/- 2%) cell suitable for use in solar energy systems but not automotive grade.
 
Completed testing of cells. Results below. Would be interested to hear from those with more experience with LiFePO4 batteries than me if these are reasonable results and in the end should I be happy with my purchase from Shenzhen Oneier Technology Co. Ltd

Capacity Test; Charge to 3.65; discharge 40A CC to 2.5V (25% sample; 4 cells out of 16 tested)




AhrsWhrs
Cell 1
285.8​
922.31​
Cell 2
279.5​
899.88​
Cell 3
284.2​
914.94​
Cell 4
281.1​
907.55​

Voltage Slump; 40A-2 minutes. (50% sample; 8 cells out of 16 tested)
Cell 1Cell 2Cell 3Cell 4Cell 5Cell 6Cell 7Cell 8
Total Sag (V)
0.059​
0.065​
0.059​
0.058​
0.067​
0.058​
0.058​
0.058​
1 sec Sag (V)
0.021​
0.025​
0.021​
0.021​
0.024​
0.021​
0.021​
0.02​
1 Sec mV/A
0.525​
0.625​
0.525​
0.525​
0.6​
0.525​
0.525​
0.5​

1665410671320.png
 
Looks like all passed, the 280K is 896WH cell so anything over this is a pass, that being said its still crap they are lasering the QR code.
 
that being said its still crap they are lasering the QR code.
I gave them that feedback and suggested that they simply market these as EVE L280K-B and label with whatever additional testing/grading standards are appropriate for storage applications. They have been straightforward in thier communications.
 
New terminals? The double threaded terminals? I believe those are Eve installed terminals.

For sun grade cells each reseller can toss what terminals on they want.
I don't know for a fact, but I think the EVE 280s are no longer manufactured for automotive use. They were reformulated for more cycles and are now just for energy storage. If you use them for solar storage and cycle them on a daily basis, that would be the best cell even if they don't pull full capacity. Before this, they were looking at a different market and had more capacity at a full 1C rate (primarily for buses and delivery trucks).
 
I don't know for a fact, but I think the EVE 280s are no longer manufactured for automotive use. They were reformulated for more cycles and are now just for energy storage. If you use them for solar storage and cycle them on a daily basis, that would be the best cell even if they don't pull full capacity. Before this, they were looking at a different market and had more capacity at a full 1C rate (primarily for buses and delivery trucks).
They cut the C rate in half and extended the cycles to about double, from the LF280N to the LF280K.
 
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