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New to buying raw cells, are these EVE LF304 cells new/ok?

yakfish

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Joined
Mar 23, 2022
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Hi, first off I'm pretty new to this, so please be nice. :)

Last year, I purchased (from Jenny Wu @ Docan) a set of 8 LF50K cells for a small 50Ah 24v motorized kayak battery build, and the cells were VERY flat. Battery works great.

I just purchased another set of 8 LF304K cells from the same source, for a 24V travel trailer build. Some are flatter than others but all seem to have at least some low point in the middle, and some higher points on each side. Hard to capture, but here's a photo - this is probably one of the worst. I'm wondering if this is "normal" for LF304's, or if these look used or just lower grade "storage grade" new cells? Anything to worry about?

The QR code on all 8 cells decodes to say they were made last July 2022.

Quote from the seller - "they are brand new EVE LF304 cells".

Thoughts?

Thanks!


IMG_8990.jpg
 
Yeah, most of them that is not possible... View attachment 141028View attachment 141029

Hard to tell get a better picture of the QR code but they appear to be a bit puffy but not horrible.

If they don't have a B on them these should be grade A as EVE started marking cells with the letter B on them made after March 2022 and these look to be July 2022.

You may need to peel off the black paper and see the area where the QR code to make sure it has not be re-lasered.
 
Hard to tell get a better picture of the QR code but they appear to be a bit puffy but not horrible.

If they don't have a B on them these should be grade A as EVE started marking cells with the letter B on them made after March 2022 and these look to be July 2022.

You may need to peel off the black paper and see the area where the QR code to make sure it has not be re-lasered.

Ok, it looks like there was probably some lasering going on here... large area around the QR has a different shine.

These were not sold to me as "Certified Automotive" but as "They are all brand new and solar storage cells." So I'm thinking they are (hopefully) new but didn't meet the automotive checks, marked as B by Eve, new QR codes etched for whatever reason... and hopefully they should still be ok cells for storage (travel trailer - solar, multiplus charger/inverter, ...) use?

OR... they are totally faked QR codes and the date codes are not trust worthy at all... :/
IMG_8995.jpg
 
Damn...

well it was only a matter of time:


and


so Add Docan to the list of re-lazering crew. Another reason why you should buy from 18650store who sells grade B but doesn't lie about it.
 
I don't see you applying any pressure in these pictures.

Bloating is due to the production of gasses that inflate the case. The walls of the cell are very thin and can be easily deformed.

Do the cells give when you squeeze the fattest parts by hand?
Yeah I didn't have anyone to help me take a picture. I can not notice any difference in the shape/gap, while pushing the cells together.
 
So what do you all think? Do these cells look new and just "grade b" cells from EVE and re-lasered to remove the "B", or used and re-lasered QR codes to hide the original dates?
 
Yeah, but you can check more qr codes ot be sure...
I'm not following... check if they are all lasered off like the one in the photo? Still not sure whether these are just B's pretending to be A's, or 2yr old cells that have been worked and re-labeled as July 2022... :/
 
I saw this video from grantipeter


So what they are doing is SANDING off the original qr code and now re-lasering an entirely new QR code over the original.

Honestly you can not even tell the difference without peeling. ?
 
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The sanding thing is new to me, I'm sure the next step is going to be to take surfacing router bit and level the entire top so it can not be distinguished.
 
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