Poor Docan Experience (Resolved)

basecamp

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Purchased 16 eve 280k from Docan over a month ago confirming the description had them as brand new, full capacity cells. Cells arrived bloated, more than 5mm out of spec at only 3.2v. No grade B QR and had the front labels that they had been "tested" at 280ah and matching IR .19.
- Reached out immediately to let them know they arrived too bloated to be "top quality".
- Tested as a pack with ebd-a20h and JK bms. Pulled 261ah.
- Requested exchange. Was then told they required individual cells which of course takes forever but did it anyway.
- None pull capacity about half in the 260s and half in the 270s. Send back screenshots of the ebd-a20h results for each. Sends a different item description than was up when I put them in my cart advertising a lower capacity. At which point the still refuse to exchange and offer a refund of $91.... saying they give a $1 per missing ah..
Regret not going with Current Connected. Theirs were grade B but guaranteed at 280ah for the same price at the time.
At this point plan to just ship back (USA warehouse) and do a credit card chargeback, unless anyone here has had success escalating a similar issue.
 
Okay we have seen enough of this to now officially call them out on it, those 280 amp hour cells are just not the same quality that they were originally shipping out and got a good reputation for.
Unfortunately they are probably getting screwed from above but regardless as far as we are concerned they are the supplier and they need to make it right.
 
Purchased 16 eve 280k from Docan over a month ago confirming the description had them as brand new, full capacity cells. Cells arrived bloated, more than 5mm out of spec at only 3.2v. No grade B QR and had the front labels that they had been "tested" at 280ah and matching IR .19.
- Reached out immediately to let them know they arrived too bloated to be "top quality".
- Tested as a pack with ebd-a20h and JK bms. Pulled 261ah.
- Requested exchange. Was then told they required individual cells which of course takes forever but did it anyway.
- None pull capacity about half in the 260s and half in the 270s. Send back screenshots of the ebd-a20h results for each. Sends a different item description than was up when I put them in my cart advertising a lower capacity. At which point the still refuse to exchange and offer a refund of $91.... saying they give a $1 per missing ah..
Regret not going with Current Connected. Theirs were grade B but guaranteed at 280ah for the same price at the time.
At this point plan to just ship back (USA warehouse) and do a credit card chargeback, unless anyone here has had success escalating a similar issue.
What were you watt-hour readings for these tests?
 
Purchased 16 eve 280k from Docan over a month ago confirming the description had them as brand new, full capacity cells. Cells arrived bloated, more than 5mm out of spec at only 3.2v. No grade B QR and had the front labels that they had been "tested" at 280ah and matching IR .19.
- Reached out immediately to let them know they arrived too bloated to be "top quality".
- Tested as a pack with ebd-a20h and JK bms. Pulled 261ah.
- Requested exchange. Was then told they required individual cells which of course takes forever but did it anyway.
- None pull capacity about half in the 260s and half in the 270s. Send back screenshots of the ebd-a20h results for each. Sends a different item description than was up when I put them in my cart advertising a lower capacity. At which point the still refuse to exchange and offer a refund of $91.... saying they give a $1 per missing ah..
Regret not going with Current Connected. Theirs were grade B but guaranteed at 280ah for the same price at the time.
At this point plan to just ship back (USA warehouse) and do a credit card chargeback, unless anyone here has had success escalating a similar issue.
can you share some pictures and graphs of the tests you performed as required by forum rules?
would be interested in seeing those graphs myself
 
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Now that I've opened a Paypal dispute, suddenly they will take a return at my shipping cost and after they "carefully check for any damage". Going to leave the Paypal dispute open till then since they have been kept inside this whole time, only attached to test equipment, and will be shipped back in their own packaging nothing should be considered my responsibility.

Frustrating to have to deal with shipping them back. Given I'll be using them for storage I would have taken a reasonable discount, but the offered $91 on a $2500 order was more insulting than helpful. Aside the hassle of testing individually, they are bloated to the point of me having to rework my enclosure.
 

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What a pain it is to deal with these turds. Never accept anything less than what's owed to you and use PayPal as much as possible. These sellers sell first, then try to make good on it second.

I've never bought anything from Docan, but did add an 8-pack to my cart...as I have with several other online companies that sell EVE, CATL, etc cells. I must have created an account with my email because I got this solicitation yesterday:

Dear customer,

Here is Amy Zheng from Docan. Nice to meet you and serve you.

Just wondering is there still need any batteries for a new project? or Do you need other BMS, Battery capacity, voltage tester, Battery separators or extra busbars together?

Amy guarantee that you can received high quality battery,please check the Order Arrangement Process:
* One battery with one bus bar and two nuts for free;
*Strong welding process.
* Top quality. Brand new and unused guaranteed;
* Matched and tested the IR and voltage over 3 times before delivery;
*Tested results shows on each battery sticker
* Strong foam packing protectioin
*Packed well and mark your name to avoid boxs missing.
* 5 years warranty;

Support fully refund if bad quality received from us.Docan Amy Zheng are highly recommended by DIY solar forum and Will Prowse website

Kind regards
Amy Zheng
 
If you buy from Docan, one thing I would be very careful of is taking a screenshot of the product description when you order. Fortunately I have one, but they tried to quote a different one in justifying the low pull. Going back and watching the website I realized they seem to adjust the description without creating a new product listing. Even if I login and go to my order history, the description it pulls up is different than from what I ordered and what they tried to quote me. So at least three different descriptions in fairly recent history.

My guess is after getting low pull reports they updated it so they could claim that was how it was sold.
Attached is my screenshot
This is the link they sent me while trying to get a refund
And this link is what my order history shows
And this is the same link using the internet archive to show the same product id with a different description
 

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Now that I've opened a Paypal dispute, suddenly they will take a return at my shipping cost and after they "carefully check for any damage". Going to leave the Paypal dispute open till then since they have been kept inside this whole time, only attached to test equipment, and will be shipped back in their own packaging nothing should be considered my responsibility.

Frustrating to have to deal with shipping them back. Given I'll be using them for storage I would have taken a reasonable discount, but the offered $91 on a $2500 order was more insulting than helpful. Aside the hassle of testing individually, they are bloated to the point of me having to rework my enclosure.
is it me, or did i see 1 cell not pulling around 270ah ?
that is 95% of capacity
are you sure itś worth opening a dispute for that ?
did you contact them to get your concerns addressed ?
 
also bear in mind that partly EVE is to blame here..
from what i heard they had a huge automotive order cancelled, and they shipped these cells off to their distri's as grade a, new , which seem not the case.
I firstly contact docan and express you concern and see what they come back with
 
Like I said, I would rather take a reasonable discount and have been going back and forth with them for several weeks. At this point the bigger problem than the capacity itself is the shady sales tactic.
- Sold saying they personally tested them to pull full capacity and were brand new "NEW K version, Only Top Grade, Brand new with Factory
intact QR code, the discharge capacity of each cell can reach 280Ah after our test."
- Then on the same product listing, after sell changed the description to say "capacity is around 270-285Ah"
- Cells came with the Docan "test" label asserting they had tested the capacity and IR which they clearly didn't

261ah as a pack is 33% of the degredation to the warrantied 80% capacity you shouldn't be hitting till reported EoL
But with all that, yes I'm using it for storage and would accept a reasonable discount. But if you are going to say you've tested something to pull capacity as a way to sell over the competition, but haven't actually done that you can't turn around and say oops it's the manufacturers fault it didn't.
 
Like I said, I would rather take a reasonable discount and have been going back and forth with them for several weeks. At this point the bigger problem than the capacity itself is the shady sales tactic.
- Sold saying they personally tested them to pull full capacity and were brand new "NEW K version, Only Top Grade, Brand new with Factory
intact QR code, the discharge capacity of each cell can reach 280Ah after our test."
- Then on the same product listing, after sell changed the description to say "capacity is around 270-285Ah"
- Cells came with the Docan "test" label asserting they had tested the capacity and IR which they clearly didn't

261ah as a pack is 33% of the degredation to the warrantied 80% capacity you shouldn't be hitting till reported EoL
But with all that, yes I'm using it for storage and would accept a reasonable discount. But if you are going to say you've tested something to pull capacity as a way to sell over the competition, but haven't actually done that you can't turn around and say oops it's the manufacturers fault it didn't.
in your posted test results there was 1 cell charging/discharging to 261 ah, the others seem to much closer to 270.
"shady" is rather overstating it, you are buying b grade cells for the prices they state, you know this, so you know you are taking a chance

if you do not want to take a chance, buy true automotive grade cells, but be prepared to pay up to 170-190 usd per cell.

i said before , this "b" qr business by eve, global battery cell shortages, covid , and shipping issues, make this a extremely bad time to be buying cells
 
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Stating in the product description that post manufacturing, you as the seller, tested the capacity when you didn't. Then when becomes a problem, revising your product description and pretending like that was the description all along doesn't count as "shady"?

To your point if they had not claimed to have tested themselves and going as far as to put that test label on the cells, I would agree it's in normal range for a grade B cell. But they did make the claim and that claim was why I went with them over others.
 
The only one that I would accept is the one that you pulled 880 Watt-hour. That seems ok about 16 WH short but this is within the margin of error, the rest that you are getting 850-860 are definitely grade B flakey cells. Don't look at the AH by itself.

BUT I want to to tell you, even the grade A/EV grade are not THAT much better. My Luyuan matched & batch genuine cells only pull slightly more Watt-hours about 896-906.

I have come to the conclusion that the 280K is a dud cell vs the original 280N or the 304.

That being said Docan has been and always be a grade B seller so its the luck of the draw. You are like 1 out of 20 people that actually bothers testing there cells, most people do not.

Good you bought form the USA warehouse so you are not stuck with these.
 
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I found something interesting Look at your cell 1 it is 274Ah and WH is 880 then compare it to cell 7 it is 274 but is 866 WH

The average voltage of the cell is 3.2V but the average voltage of cell 7 is 3.16V

So at first glance people would say well both cell 1 and cell 7 are 274Ah are the same. But this is not true, cell 1 is a better cell and has more watt-hour and its average voltage during the test was 3.2v vs 3.16v for cell 7
 
I found something interesting Look at your cell 1 it is 274Ah and WH is 880 then compare it to cell 7 it is 274 but is 866 WH

The average voltage of the cell is 3.2V but the average voltage of cell 7 is 3.16V

So at first glance people would say well both cell 1 and cell 7 are 274Ah are the same. But this is not true, cell 1 is a better cell and has more watt-hour and its average voltage during the test was 3.2v vs 3.16v for cell 7
So this is the problem trying to compare watt hours.

You see different watt hours and assume the cells are different. How do you know that the resistance of the connections to the cell wasn't different for one cell than the other? That would also cause the watt hours to be different.

The only real way to show a difference in cells quality is to do a true DC internal resistance measurement. I've been trying to think through of a way to do this at home using my volt and amp meter, without a lot of expense for specialized equipment.
 
So this is the problem trying to compare watt hours.

You see different watt hours and assume the cells are different. How do you know that the resistance of the connections to the cell wasn't different for one cell than the other? That would also cause the watt hours to be different.

The only real way to show a difference in cells quality is to do a true DC internal resistance measurement. I've been trying to think through of a way to do this at home using my volt and amp meter, without a lot of expense for specialized equipment.
 
So this is the problem trying to compare watt hours.
I do think Watthours is a better metric for me to use to compare price per Watthour and capacity because all of my consumption and generation figures are in thousands of Watthours (kWhs). I did spend time when assembling my pack to eliminate any significant resistance in the connections.
 
Thanks for the suggestion, but I already have one of those. I think they are good for checking connection resistance, and I did use it to test all my cells. However, the manual says it is not for testing large cells. It is an AC resistance tester, and I think in larger cells capacitance and surface effects hide the true resistance of the cell.

I want to be able to pull 150 amps from a cell for 30 seconds and watch the voltage sag, and then see if that is a useful metric to compare cells.
 
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