Docan Power US Warehouse LF280K Review

[zcskywire2]

So I have an idea about what's going on here. I've recently got some cells from Docan out of Texas. These were both LF280Ks and LF304s. When I received them, I noted that the LF208Ks and LF304s had different labels. They are different cells however, and frankly I though nothing more of it. Seeing this post I went back and confirmed that they were re-lasered. However I looked at the QR codes on Lt Dan's Cells and mine, They are clearly different text printing for the "lf280k line". Then I caught the stickers on his cells in the testing setup. They were not the same as my LF280K cells, instead they matched my LF304 cells. So Looking up the Ezeal chart, sure enough my LF304s were on that chart.


Re-lasered LF280K with Docan Sticker, Note the text printing difference between Lt. Dan's cell and this one on the LF280K line


Original QR LF304 with unbranded sticker, (cant peel the top sorry),


Edit: I should add, I got the LF304s right before Docan claimed to be out of stock of them. Its likely that they filled stock with with the Ezeal original QR code cells to use them up. The LF280Ks were solidly in stock when I ordered. Looking back I paid 132$/ cell for the LF280Ks and 152$ for the LF304s. Seems to line up on the pricing side for the LF304s Ezeal lists them at 155$

 

[Brett V]

 

[Lt.Dan]

The plot thickens.

 

[Alkaline]

Docan's tag line: Free Bucket of anxiety with every purchase!

 

[740GLE]

See this right here is why it’s sooo much more exciting to buy your own cells and DIY, I mean anyone can buy a server rack battery and forget about it, but where’s the sense of adventure in that?

Thanks all for the shared info, another onion layer seems to have pealed back.

 

[Lt.Dan]

Well, confirmed capacities for each cell:

Cell 1: 285ah
Cell 2: 286ah
Cell 3: 284ah
Cell 4: 286ah

I'd say its a success. But they technically do not match the data sheet that @Alkaline posted.

Amy reached out to me today to ask if I received them and if I have tested them yet. I will respond to her with this information and see how she responds.

 

[Alkaline]

You will NEVER match EVE data sheet, If anyone said they matched EVE sheet, they are full of it. Ask anyone that has tested grade A Eve cells on the ZKE40 on average about 4-5 AH lower, the K series can be 10AH lower.

It is what it is. Now this is based on our little ghetto chargers/testers, if you confront EVE about this they will say "Run along u little troll you don't have professional equipment"

Some other brands like REPT, and CALB are much closer.

If you want to feel a bit better, you can do the watt-hour/3.2 method, where you take the watt hour measured and divide by 3.2. There is some controversy with this approach though as how accurate you measured watt-hours can throw this measurement out of whack. So for most the AH seems to keep most people happy and as long as its above 280 on a 280 it is considered good.

You are lucky SOB btw you got grade A for grade B prices, go buy some lottery tickets, and see how far this train goes

 

[Alkaline]

So you can see according to the diagram, you tested to 950WH.

Watts-hr = AMP-hr * nominal voltage of chemistry

so 950 / 3.2 = 296AH close enough to the 295AH on the spreadsheet.

Again, some people are going to start throwing rocks at me so I'm leave it at that... Take it for as you will.

 

[Lt.Dan]

And the plot thickens further. I went to go assemble my 3rd Seplos Mason kit, and i put these Eve 280k cells next to some other 280ah cells I have, and they are definitely taller than the 280s.

On the left is an actual high quality 280ah cell. Same as over 60 other cells I have. The middle cell is the Docan 280k, and on the right is a 310ah cell.

Hmm. Why is the Docan 280 the same height as a 310?

 

[houseofancients]

Are these the "same" 280k cells ?

304 and 280k cell are the exact same dimensions, the older series were a bit different in size

 

[zcskywire2]

And the plot thickens further. I went to go assemble my 3rd Seplos Mason kit,
View attachment 157658

Seplos has started shipping Cornex PF173-280A cells in some kits, with out pictures I can't tell you if it's them but it would be easily noticeable.

As for why is the Docan 280 equal to the the 310? Two thoughts. Because it isn't quite clear which cell is being referred to, there are 2 cells I can think of that could be classified as a 310. The CATL CB310, which is their 280A cell. It is almost the same size as the LF280k. Otherwise and much more likely what you were referring to is the CATL 001CB0Y0 310Ah cell. This cell would be a good bit taller than the EVE LF280k, as it's 6mm taller based(213mm) on the datasheet. Vendors tend to sell high preforming CATL LEP71H3L7-01 302AH cells as the 310Ah cells however. These cells again come very close to matching the dimensions of a LF280K.

Lastly, while the cell brand isn't mentioned, the left cell in your picture appears to be a REPT CB71173204EB 280Ah cell. These cells are a little shorter than most of the rest of the 280ah field being about one millimeter shorter than the LF280k and CATL CB310 cells. Which is about what it appears in the pictures. Though with out top shots I couldn't tell you exactly what they are.

 

[Lt.Dan]

Are these the "same" 280k cells ?

304 and 280k cell are the exact same dimensions, the older series were a bit different in size

This must be it then. The cell on the left I don't know what it is. I have 12 of them that were given to me. Most of my bank is with 3 year old CATL 271ah cells, and the cell on the left in the picture and my old CATL cells are exactly the same dimensionally.

The 310ah cells I also don't know what brand they are. But seeing them look exactly like the EVE LF280K, makes me think maybe the EVE LF280K is actually a 310 that has degraded. But if the newer generations have changed, then that must be it.

Seplos has started shipping Cornex PF173-280A cells in some kits, with out pictures I can't tell you if it's them but it would be easily noticeable.

I have no Seplos cells. I'll get pics of the QR codes though.

As for why is the Docan 280 equal to the the 310? Two thoughts. Because it isn't quite clear which cell is being referred to, there are 2 cells I can think of that could be classified as a 310. The CATL CB310, which is their 280A cell. It is almost the same size as the LF280k. Otherwise and much more likely what you were referring to is the CATL 001CB0Y0 310Ah cell. This cell would be a good bit taller than the EVE LF280k, as it's 6mm taller based(213mm) on the datasheet. Vendors tend to sell high preforming CATL LEP71H3L7-01 302AH cells as the 310Ah cells however. These cells again come very close to matching the dimensions of a LF280K.

Lastly, while the cell brand isn't mentioned, the left cell in your picture appears to be a REPT CB71173204EB 280Ah cell. These cells are a little shorter than most of the rest of the 280ah field being about one millimeter shorter than the LF280k and CATL CB310 cells. Which is about what it appears in the pictures. Though with out top shots I couldn't tell you exactly what they are.

It's a lot more than 1mm. It's more like 4mm. Hopefully the QR with show more info

 

[Alkaline]

Not sure if that square terminal is an eve cell they usually use a circle...

 

[Lt.Dan]

Not sure if that square terminal is an eve cell they usually use a circle...

Yeah I don't think it's an EVE either. I have no idea who the manufacturer is

 

[Alkaline]

REPT? CALB?

 

[Horsefly]

So you can see according to the diagram, you tested to 950WH.

Watts-hr = AMP-hr * nominal voltage of chemistry

so 950 / 3.2 = 296AH close enough to the 295AH on the spreadsheet.

Again, some people are going to start throwing rocks at me so I'm leave it at that... Take it for as you will.

Not going to throw rocks - really - but...

Any legit measure of Wh simply can NOT be calculated as Ah multiplied by an arbitrary 3.2V "nominal" voltage. A measurement over time has to be measured over time. Simple as that. The cell capacity tester measures Wh and Ah over time, and that is probably more accurate than just measuring and just assuming some nominal voltage to get to an answer of Wh.

This is the very thing that turned me off to the Sun Fun Kits guy. Bad engineering math.

 

[Sam Cho TX]

I had this same question when I tested my SFK 304 cells, and the math absolutely checks out go ask https://www.reddit.com/r/AskPhysics/?rdt=56993 I forgot a link to my thread but I had a Ph.D guy from Rutgers University answer my question and he confirmed this along with another few people.

Watt-hour is the proper way to capacity test. Ah is close but WH is closer. Important thing is to make sure you have the small voltage measuring leads.

 

[zcskywire2]

REPT? CALB?

Later model REPT, Later model Ganfeng, Battero Tech, or Highstar.

Those are the only four with square on square terminals that could fit the larger square studs. Seeing as the Battero Tech are new to the Market, likely not those. I've never seen the Highstar cells outside of their store either so again likely not those. Based on the inferred height likely the REPT cells.

 

[gionny]

Hey all, I purchased 4x 280ah cells from Amy at Docan Power, I got 4x EVE LF280K cells from their US Based/Texas warehouse. I emailed Amy directly for most of the experience, docanpower22@gmail.com. She also has a Direct Work Email that is available: amy@docanpower.com.
I did not probe for a ton of questions. I did not ask for any "Guarantees" or anything. I simply stated I wanted 4x cells, with shipping to my address. The only thing I did ask, was that I confirmed they came with 6mm welded studs, so they would match my other cells I already have. She assure they would, and sent me an Invoice through Alibaba to complete the payment. It was very straight forward, and pretty easy I guess. I paid with PayPal, and had it all done pretty quickly. I paid for the order on 7/1/23.

I emailed her direct again, and asked for an estimated delivery date on 7/6/23, because I noticed the Alibaba orders page showed it had not shipped yet. She responded very quickly with both tracking numbers, being shipped via Fed Ex. Tracking showed they would show up on Monday-7/10/23. To my surprise, they showed up on Saturday 7/8/23, 2 days early.

I opened up the boxes, and they were very well packaged, and actually better packaged then I have gotten in the past. No damage, no dented corners etc. Visually they are perfect. Completely flat, nice symmetrical wrapping, the QR code looks to be in tact, without any sanding or anything. I have no proof as I haven't taken off the black plastic though. I have expressed in the past that I am not as interested in the QR code, or if it is A grade or B grade, so long as they pull capacity and are not visibly used. I have them on my desk in the office now, doing capacity tests with the EBC-A40L tester now.

My test method:
1) Fully charge at 40a to 3.65v, cutoff at 2a.
2) Wait for 30 minutes.
3) Discharge at 40a to 2.5v.
4) Charge at 40a to 3.45v, cutoff at 2a.

The first one just completed and it Discharged with 284.9Ah, it also CHARGED with 285.1Ah! Talk about a damn perfect charge efficiency lol.

I will test the other 3 and report back the results.

View attachment 156621

Capacity Testing:
View attachment 156617

Cells are very flat and uniform, even with the one with clamps having it at 3.65v, fully charged. Almost no bulging.
View attachment 156618

QR Code:
View attachment 156619

Amy Zheng è una grande truffatrice vende celle false ne ho le prove (la eve non ha venduto celle alla docan) come è capitato a me, le celle sono tutte difettose e non reggono il carico scendono subito a 2.6v e va in protezione il bms le celle vendute da alibaba dal magazzino polacco sono di produzioni diverse dal 2022 al 2023 ma tutte non sono equilibrate ogni cella va per fatti suoi in tensione da 2.5v a 3.1v non c'è ne una uguale scappate via vi rifila un bidone grande è una ladra

 

[houseofancients]

Amy Zheng è una grande truffatrice vende celle false ne ho le prove (la eve non ha venduto celle alla docan) come è capitato a me, le celle sono tutte difettose e non reggono il carico scendono subito a 2.6v e va in protezione il bms le celle vendute da alibaba dal magazzino polacco sono di produzioni diverse dal 2022 al 2023 ma tutte non sono equilibrate ogni cella va per fatti suoi in tensione da 2.5v a 3.1v non c'è ne una uguale scappate via vi rifila un bidone grande è una ladra

it would help if you posted this in english, so i translated your message...

Amy Zheng is a great scammer, she sells fake cells, I have proof of this (Eve didn't sell cells to Docan), as happened to me, the cells are all defective and can't handle the load, they immediately drop to 2.6V and the BMS goes into protection. cells sold by alibaba from the Polish warehouse are of different productions from 2022 to 2023 but all are not balanced each cell goes its own way in voltage from 2.5v to 3.1v there is none the same run away she gives you a big bin she is a thief