EVE-280 cells should these be clamped tight or spaced for expansion?

[miky]

Thanks for reply,
Very disappointed with this company. She sent me a picture of july 2020 cells and sent me this
It make me think that these are used. I can see scratches on terminals and this particular cell came with 2.94v.
I think I should start a refund process. what do you think?
I think I should warn other people with this Shenzhen Basen company!

 

[Gazoo]

From what I know of Basen they are very reliable. Are you saying all your cells are scratched and they all have the same date code? If the scratches are light it could be from testing. They claim to test the internal resistance and voltage before they send them out. The cell with the low voltage is a concern and you really won't know if it's ok until you test it. And you don't want to parallel top balance until the voltages of the cells are all close to being equal.

 

[Dzl]

August 12 2018? The code meanings are listed in the specifications. I am thinking they are new old stock.

How are you determining this?
I know the first 3 digits of the horizontal serial number refer to date, but I don't understand how to decipher it.

 

[Bob B]

Looks like it a hex code 88C .... year, month, day .... 2018, Aug, 12

 

[Gazoo]

I posted the spec sheet on the previous page. If you scroll towards the bottom you will see it.

 

[miky]

Well, my experience with them is far from reliable!
Basically they lied about cell production date, balancing and matching cells before shipping!

I already charged the low voltage cell to 3.34v and now I am top balancing them. I just ordered battery capacity test device to test them.
I just did a rough estimation of the wattage that took that cell from 2.94v to 3.34v and it was about 300-350watts. In other words, by looking at the SOC voltage it charged from about 5% to 80% and it took about 300watts. The cell capacity supposed to be 280Ax3.2V=896W. So taking only 300-350w to move the battery voltage from 5% to 80% is another red flag.
When I get the battery tester I can confirm

 

[Dzl]

I posted the spec sheet on the previous page. If you scroll towards the bottom you will see it.

Thanks, I see that, I just don't know how to make sense of the 3 digit date codes

Looks like it a hex code 88C .... year, month, day .... 2018, Aug, 12

Thanks Bob, I don't entirely understand Hex, but I just wikipedia'd it. 16 digit number system 0-F.

So for example
2018-August-12 = 88C
2018-July-8 = 878
2019-January-30 = 91??
2020-December-1 = 0C1

 

[Bob B]

Thanks, I see that, I just don't know how to make sense of the 3 digit date codes



Thanks Bob, I don't entirely understand Hex, but I just wikipedia'd it. 16 digit number system 0-F.

So for example
2018-August-12 = 88C
2018-July-8 = 878
2019-January-30 = 91??
2020-December-1 = 0C1

HMMM ... I don't know how it works for a day greater than 16 .... Your other examples looks as I would think ...

 

[Dzl]

Very disappointed with this company. She sent me a picture of july 2020 cells and sent me this
It make me think that these are used. I can see scratches on terminals and this particular cell came with 2.94v.
..
I think I should warn other people with this Shenzhen Basen company!

Would you share the picture that shows July 2020 production date?

I don't believe I've seen anyone receive cells newer than 2018, from Xuba, Basen, Lightning, etc. Though in the vast majority of cases (99%) date of manufacture is not known or not posted publicly here.

Old production date doesn't necessarily signify used cells, they are just as likely to be (much more likely in my opinion) to be new-old-stock being sold off at a discount as they can no longer be sold as new grade A through official channels. This would also explain why some sellers are warning that they are drying up.

Further, lightly scratched terminals are somewhat normal from what I've read, cells are tested at the factory and possibly again by middlemen.

I think I should start a refund process. what do you think?

If it were me, I would balance and capacity test the cells before attempting a refund (I'm not even sure you have grounds for a refund (apart from the low voltage cell if its bad) unless Basen explicitly stated your cells were from 2020, or explicitly represented the picture as your specific cells).

You may have a bad or weak cell, or at the least a cell that was not matched to the others based on voltage. Definitely worth investigating

If they did explicitly misrepresent the cells as being produced in July 2020, that is disingenous and bad business.


As to:

Basically they lied about cell production date, balancing and matching cells before shipping!

Are you sure you correctly understood them, and they correctly understood you? No grey market reseller that I am aware of will balance the cells for you. Best you will get is voltage matching and maybe basic IR matching depending on reseller, which from the sound of it, they screwed up with at least 1 cell, unless the problem occurred during transit.

Best of luck with the testing, hopefully it was just stored at a lower voltage and its a healthy cell, if not, I would definitely pursue replacement of that cell.

 

[Gazoo]

The cell capacity supposed to be 280Ax3.2V=896W. So taking only 300-350w to move the battery voltage from 5% to 80% is another red flag.

Around 3.2 volts is the resting voltage of a cell fully charged to 3.65 volts.

 

[miky]

Would you share the picture that shows July 2020 production date?

I don't believe I've seen anyone receive cells newer than 2018, from Xuba, Basen, Lightning, etc. Though in the vast majority of cases (99%) date of manufacture is not known or not posted publicly here.

Old production date doesn't necessarily signify used cells, they are just as likely to be (much more likely in my opinion) to be new-old-stock being sold off at a discount as they can no longer be sold as new grade A through official channels. This would also explain why some sellers are warning that they are drying up.

Further, lightly scratched terminals are somewhat normal from what I've read, cells are tested at the factory and possibly again by middlemen.



If it were me, I would balance and capacity test the cells before attempting a refund (I'm not even sure you have grounds for a refund (apart from the low voltage cell if its bad) unless Basen explicitly stated your cells were from 2020, or explicitly represented the picture as your specific cells).

You may have a bad or weak cell, or at the least a cell that was not matched to the others based on voltage. Definitely worth investigating

If they did explicitly misrepresent the cells as being produced in July 2020, that is disingenous and bad business.


As to:



Are you sure you correctly understood them, and they correctly understood you? No grey market reseller that I am aware of will balance the cells for you. Best you will get is voltage matching and maybe basic IR matching depending on reseller, which from the sound of it, they screwed up with at least 1 cell, unless the problem occurred during transit.

Best of luck with the testing, hopefully it was just stored at a lower voltage and its a healthy cell, if not, I would definitely pursue replacement of that cell.

 

[miky]

Around 3.2 volts is the resting voltage of a cell fully charged to 3.65 volts.

Thanks for note, since I did not let the cell rest enough (maybe 30 minutes) I underestimated the SOC to be fair.
Obviously when discharging with test device the right capacity number will be determined.

 

[Dzl]

Hmm,
Well I can certainly see why you would expect the cells would be 2020 cells based on that exchange. Basen did not say it explicitly, (they said they received the cells in July, and that they are 'brand new') And if they added the red boxes to the image, the date they highlighted roughly translates to "Production Date: 2020.7.10" and the next line down says "Shipping Date 2020.7.11." If they added the red boxes they definitely explicitly gave you reason to believe the cells were produced in 2020.



One complicating factor is that that label appears to be the shipping label from the wholesaler or middleman or manufacturer, it is quite possible the cells are being represented to Basen this way. Of course they should be doing there due diligence and have knowledge of the product they are selling and represent it accurately. Realistically, I don't have great faith in resellers knowing the product they sell in great detail, or being willing to do the digging if it doesn't benefit them.

 

[Ampster]

I have an order coming in 30 days. I researched the company and dont care about scratches or dates. All that matters to me is capacity and performance. I am not getting married to them.
?‍?

 

[Dzl]

I have an order coming in 30 days. I researched the company and dont care about scratches or dates. All that matters to me is capacity and performance. I am not getting married to them.
?‍?

Minor cratches are a non-issue in my eyes, date of manufacture is more of a relevant indicator though. As stated, I have not seen any EVE cells from any reseller newer than 2018 (99% of people don't show or read QR codes so there could be tons that are newer or older). And the LF280N datasheet is dated 2019, I suspect all LF280(non-N) cells are older than 2019.

That said, their are reasons I would pay attention to date of manufacture (1 potentially positive, 1 potentially negative)
(1) Calendar Aging: Capacity loss over time, I'm not sure how much of an issue this is or isn't if cells have been properly stored (~25*C, ~30-60% SOC). It is a bigger deal at higher SOC and especially higher temperatures.
(2) The silver lining: There is a reason these cells are as cheap as they are, one of the least bad reasons this could be in my eyes is they are new-old-stock grade A or A- cells that can no longer be sold as such through legit channels.

At the end of the day, if they meet your needs they meet your needs, and they are a good price.

 

[miky]

Hmm,
Well I can certainly see why you would expect the cells would be 2020 cells based on that exchange. Basen did not say it explicitly, (they said they received the cells in July, and that they are 'brand new') And if they added the red boxes to the image, the date they highlighted roughly translates to "Production Date: 2020.7.10" and the next line down says "Shipping Date 2020.7.11." If they added the red boxes they definitely explicitly gave you reason to believe the cells were produced in 2020.

View attachment 23761

One complicating factor is that that label appears to be the shipping label from the wholesaler or middleman or manufacturer, it is quite possible the cells are being represented to Basen this way. Of course they should be doing there due diligence and have knowledge of the product they are selling and represent it accurately. Realistically, I don't have great faith in resellers knowing the product they sell in great detail, or being willing to do the digging if it doesn't benefit them.

The red boxes are added by them. The reason is that I was not sure which seller to buy from and she sent me this picture to show me that cells she send me are brand new 2020.

Hmm,
Well I can certainly see why you would expect the cells would be 2020 cells based on that exchange. Basen did not say it explicitly, (they said they received the cells in July, and that they are 'brand new') And if they added the red boxes to the image, the date they highlighted roughly translates to "Production Date: 2020.7.10" and the next line down says "Shipping Date 2020.7.11." If they added the red boxes they definitely explicitly gave you reason to believe the cells were produced in 2020.

View attachment 23761

One complicating factor is that that label appears to be the shipping label from the wholesaler or middleman or manufacturer, it is quite possible the cells are being represented to Basen this way. Of course they should be doing there due diligence and have knowledge of the product they are selling and represent it accurately. Realistically, I don't have great faith in resellers knowing the product they sell in great detail, or being willing to do the digging if it doesn't benefit them.

The Red box was added by them by seller to assure me the cells are production of 2020.
This is the message I received from her few minutes ago " These cells are produced on July 2020."
I sent her barcode and Eve cell barcode reading instruction and now she says she has to talk to her supervisor.

 

[miky]

I have an order coming in 30 days. I researched the company and dont care about scratches or dates. All that matters to me is capacity and performance. I am not getting married to them.
?‍?

I agree with you. I just wanted to be 2020 production to take less chances of having defective cells.

 

[Gazoo]

I would parallel top balance the cells then run a capacity test. Or test each cell individually. If the cells are at or close to their advertised rating then you could negotiate a partial refund since they told you the cells were manufactured in 2020. You have double proof of them telling you that. I do not think you will get a full refund except for the one cell if it's bad. On the bright side Basen now knows we know how to read the date code....lol.

I am disappointed it appears they lied to you. You are the only one I have known of that has asked for recent production 280ah cells. As far as I know the only way to get fresh recently produced 280ah cells is to order directly from EVE. But then the price goes way up.

Good luck and please let us know how this works out for you.

 

[miky]

I agree with you guys that after all what we want is matched healthy cells. I just wanted to share my experience with this company. Thanks for support.
Here are the pictures of cells. The cell on bottom is the cell that came with 2.94v. The rest were 3.34v. You may notice a slightly different design of barcode of low voltage cell as well.

 

[Dzl]

I am disappointed it appears they lied to you. You are the only one I have known of that has asked for recent production 280ah cells. As far as I know the only way to get fresh recently produced 280ah cells is to order directly from EVE. But then the price goes way up.

Personally I think it is way to early to infer that Basen lied. It is clear they are not 2020 cells, and it is clear they were (mis)represented as 2020 cells, but it is far from clear (to me) that Basen intentionally or knowingly misrepresented them. This is based on my assumption that that packaging label was the label they received and not a label they printed (but maybe I am misinterpreting this).

I have a few pessimistic maybe realistic baseline assumptions:
Grey market resellers sometimes don't know a lot about what they are selling, in many cases less than the collective community knowledge found here.
Grey market resellers don't necessarily want to spend time digging for info if they won't like what they find.
Grey market resellers may or may not be buying directly from the manufacturer (there may be additional middlemen/wholesalers).