Where are you getting this from?
Here I've been monitoring 280K for 3-4 months now:
LF280K will barely meet AH, but will exceed the WH, the 280K is a 280AH cell and is a 896WH cell, here are grade A results (with manufacturer test reports)
My Results
278.4 & 901.4 WH, Luyuan Test Report said I should be getting
289.4 AH on these Matched & Batched Cells Genuine grade A:
https://diysolarforum.com/threads/what-is-going-on-here-just-got-zke-40.49076/
shane_Uk with Luyuan Genuine matched & batch results
276 AH vs the 289 Ah on the sheet; did not show WH, but I suspect it would probably be around 900 or more:
https://diysolarforum.com/threads/opinions-welcome-for-newbie-lifepo4-battery.47310/
18650batterystore.com grade A results, a person named Dena M. Says
277.7 AH (did not show WH, but again I suspect it would be around 900ish maybe 901):
https://www.18650batterystore.com/products/eve-lf280k#looxReviews
Fogstar UK grade A EVE 280, Cajocars gets
280.5 AH & 907.5 WH EVE stated Capacity was supposed to be
293.9 AH…, but still first person with a 280K to actually break the 280 barrier…but just barely
https://diysolarforum.com/threads/just-bought-16-280ah-a-grade-from-fogstar.51027/page-3#post-662021
NKON grade A results by Delphinus
279.95 AH & 905 WH
I have just recieved 64 EVE 280K cells and tested so far 10 of them with the ZKE 40 tester. So far one was 280AH the other 9 between 260 and 270. I want to post the full results when done with all testing. But so far results look identical as what is described here.
diysolarforum.com
So something is up, grade A 280K with manufacturing test report are having a hard time meeting the 280AH capacity which is very different form the original 280N and current 304, as these have NO problems meeting both AH and WH.
Grade B 280k:
Docan 280K results, very detailed thread by basecamp, but average
263 AH and 850WH
https://diysolarforum.com/threads/poor-docan-experience-resolved.48592/#post-618121
Docan 280K Results by Ce Ce,
265 WH and 860 WH, tested a few cells but this was the average:
https://diysolarforum.com/threads/disappointing-eve-280k-results.47555/
Docan 280K results by gonmag8
265 AH & 863.5 WH:
https://diysolarforum.com/threads/disappointing-eve-280k-results.47555/post-606579
Docan 280K by atti
270Ah & unknown WH:
https://diysolarforum.com/threads/eve-lf280k-capacity-test.49961/
These issues don't exist with the LF304, OR LF230 or the CATL 280, or REPT 280, these cells even grade B will for the most part meet capacity in AH and WH.
But specifically the 280K seems to have an issue, I used to think it was a certain date range, but now I see even cells made in October 2022 are acting the same way so EVE has made these cells this way.
I don't know if this is bad or not, but we have all come accustomed to judging cells mainly by AH so take the above as you will. I had 3 x 8s setups, I just sold them all but I was happiest with my Liyuan 280K grade A out of them all, and in the future I will probably go with grade A LF304.