Eve 105 with questionable (reprinted?) QR code

[marksman]

After the Liitokala disaster I saved some money and ordered 16 Eve 105 (grade A) from nkon.nl hoping that I will avoid any other headache related to quality of the cells.

The cells arrived in two boxes, let's call them Box A and Box B, all around 3.29x V. All QR codes turned out valid on Gobel site and using the Android LifePo4QR reader. I've put Box A through the top balance process using a benchtop power supply, following the top balance tutorial on this forum. It took a week to balance to 3.650 V due to 10 A limitation of the power supply. I've assembled Box A into a battery and things seem good.
I then put Box B through the top balance process and now things started to look weird: as opposed to Box A, the initial charging current started at around 9 A. When Box A was top balacing it started at 9.8-ish A and it took two days to drop to 8 A, which seemed consistent with 105 Ah rating. Now it took just under one hour to get from around 9 A to 7.97 A and under 24 h to drop somewhere in the low 6 A. This does not seem consistent with declared capacity of 105 Ah.
And then I noticed something else: from 8 cells in Box B there is only one with laser etched QR code, all others are stickered. As far as I know Eve uses lasered etched codes only. The cells in Box A all had laser etched QR codes.
So what I suspect is that whoever Nkon bought from sold a batch of doctored cells that pretend to be real Eve 105s while they really could be 90Ks or something else, even 75s, since the physical dimensions are identical between them. The cells looked all new and I didn't notice the QR difference at first due to lighting, late hours and tiredness. I've emailed nkon on the subject and asked to solve this.

I've attached some pictures. In the first picture you can see the Box A while top balancing. When enlarging one can see the QR area is not shiney as there are no stickers there. Better view of this is in the last picture, top is Box A, bottom is Box B, you can see the differences and even spot the single etched QR. Second and third picture show Box B, you can see detail between laser etching and sticker.

LE: there was no test report in the boxes and nothing to identify the cells for warranty purposes.

 

[Steve_S]

I can tell you that EVE Never Ever uses "stickers" as such. There are instances where they have reprinted the QR Code which is lasered onto the aluminum so they can relocate it on the cover (by special request for a VAR and rarely so).
The laser printing is ALWAYS perfectly aligned & squared on the cells...

Unfortunately the last image is no clear enough when zoomed in on (limit of forum software, only 1 level of zoom).

Note that just because the Cell Voltage was 3.290, that is "surface charge" and not much of an indicator. Now if you charge a cell to 3.300 and allow it to drop down to taking only 2A at that voltage, it will be pretty saturated to that point. If you do hat with another cell but only let it drop to only taking 8A is will not be saturated and will take a lot more to start going up in voltage again. Simplest Explanation.

EVE 105AH cells have an EndAmps/Tailcurrent of 5.25A which means that when charging up, when they drop to taking only 5A they are "full" for all intents & purposes. During the TOP BALANCE process we often let that go a bit further down to around 2 or 3 amps, lower is not really good but OK if you only do it ONCE. Once fully Top Charged & Activated the cells are ready for testing capacity.

PROPER TEST !
Here we go again.
LFP like all chemistries has TWO Voltage Curves...
1) is the Allowable Voltage Range which cases no harm or wear on the cells, that range is from 2.500 to 3.650 Volts per cell. This is NOT for regular use. Think of it like filling you car gas tank will it flows out the filler neck, Not Good !
2) The Working Voltage Range is the range that is supposed to actually deliver the rated Amp Hours of the cells. This range is from 3.000-3.400 Volts, due to the very flat Voltage Curve of LFP. This IS the range that companies test to validate the cells and true A-Grade cells will deliver the rated AH from the working range.

When testing, start 1 Hour after charging the cells to 3.500 / 14.0V and stop the discharge at 2.900 (that should recover to 3.0 or close post discharge)

This quick chart below may be of help to you...
BTW: Be careful, there are many people who like to tell people "overfill the tank" and have fun troubleshooting the issues that come up... Do not push the batteries beyond design spec and limits.

 

[Pi Curio]

Thanks for sharing!

Was planning to make an order for a whole bunch of EVE 304Ah cells, but I don't like what I see here.

Did you contact their customer support?

 

[Steve_S]

Thanks for sharing!

Was planning to make an order for a whole bunch of EVE 304Ah cells, but I don't like what I see here.

Did you contact their customer support?

You CAN get Real/Genuine & Proper Grade-A Cells with Factory test reports if you want... but Penny pinching to save the $5 per cell will likely cost you far more... IS some folks buy extra cells and end up with spares and if you consider a 304 is around $80 ea, that is quite stupid financially. Start with a GOOD SOLID FOUNDATION and then build your house on it... Cheap out and suffer the consequences.

There is ONE BIG TRUTH IN SOLAR !
Penny Wise = Dollar Foolish ! Scrimp here & there and it ALWAYS comes back to bite you in the backside while ripping your wallet from you.
Ask yourself, would you skimp of Fuses & Breakers so save a few cents & risk your home & life ? So the Top Grade fuse is $20 but you can get a cheapo for $15, which is smarter ?

 

[marksman]

Thanks for sharing!

Was planning to make an order for a whole bunch of EVE 304Ah cells, but I don't like what I see here.

Did you contact their customer support?

Yes, as written in the initial post, I've contacted them to ask to solve this.

 

[Pi Curio]

You CAN get Real/Genuine & Proper Grade-A Cells with Factory test reports if you want... but Penny pinching to save the $5 per cell will likely cost you far more... IS some folks buy extra cells and end up with spares and if you consider a 304 is around $80 ea, that is quite stupid financially. Start with a GOOD SOLID FOUNDATION and then build your house on it... Cheap out and suffer the consequences.

There is ONE BIG TRUTH IN SOLAR !
Penny Wise = Dollar Foolish ! Scrimp here & there and it ALWAYS comes back to bite you in the backside while ripping your wallet from you.
Ask yourself, would you skimp of Fuses & Breakers so save a few cents & risk your home & life ? So the Top Grade fuse is $20 but you can get a cheapo for $15, which is smarter ?

Not sure if I understand correctly what you meant to say.

However, I agree with you. Why I would consider buying only A-grade cells from a known seller located in the EU.

The thing is, he said he ordered EVE 105Ah A-grade from NKON for which they claim that these are not leftovers, and come straight from the EVE manufacturer. Those printed QR codes leave much to be desired, don't you think?

I also ordered EVE 105Ah A-grade cells last year from NKON, the QR codes looked legit. Nothing like in the OP pictures.

Makes me wonder, is there some change in how NKON does business I should know about before making my order for my final battery storage build.

 

[Pi Curio]

Yes, as written in the initial post, I've contacted them to ask to solve this.

Following with interest!

 

[marksman]

You CAN get Real/Genuine & Proper Grade-A Cells with Factory test reports if you want... but Penny pinching to save the $5 per cell will likely cost you far more...

Initially I wanted to order 100 Ah cells from GWL. They make their own (well, actually the cells are made in Chinese factories as far as I understand) and they test them and provide test reports. The price difference was, well, significant and I've read good reviews regarding nkon.

 

[houseofancients]

You CAN get Real/Genuine & Proper Grade-A Cells with Factory test reports if you want... but Penny pinching to save the $5 per cell will likely cost you far more... IS some folks buy extra cells and end up with spares and if you consider a 304 is around $80 ea, that is quite stupid financially. Start with a GOOD SOLID FOUNDATION and then build your house on it... Cheap out and suffer the consequences.

There is ONE BIG TRUTH IN SOLAR !
Penny Wise = Dollar Foolish ! Scrimp here & there and it ALWAYS comes back to bite you in the backside while ripping your wallet from you.
Ask yourself, would you skimp of Fuses & Breakers so save a few cents & risk your home & life ? So the Top Grade fuse is $20 but you can get a cheapo for $15, which is smarter ?

Nkon does sell true a grade eve cells, with eve test report, and yes they are more expensive.

 

[Steve_S]

People are always trying to save a few dollars here & there and if done smartly & wisely can accomplish that.
Solar Panels being ONE... Far too many buy whatever they can find at cheapest per watt price and not even considering if it is the Right Panel for the site... Some are better for Shade & Cloud (living in a forest for example) while others are best in pure open-sky country... some are better in Hot Conditions (pick a desert) while some perform better in colder temps. You'd be shocked at what a difference there is.

Some people buy the cheapest cells they can find - IE pay for a Chevette and expect a Rolls Royce and will actually believe the Polyester Clad Sales Rep who knows nothing other than is what is on their script. Then these folks come here & argue how they got screwed and how the manufacturer is at fault...

 

[Pi Curio]

Nkon does sell true a grade eve cells, with eve test report, and yes they are more expensive.

Curious.

Can you walk me through how to order true A-grade cells from NKON? Do I have to contact them first and specify I want the A-grade cells, or I can just order from their website?

The last time I ordered the cells, they came without the test report. Upon request for it via customer support email, I got the PDF after providing the cell code.

Is your experience similar?


Thanks.

 

[marksman]

Nkon does sell true a grade eve cells, with eve test report, and yes they are more expensive.

There is only one item advertised as grade A 105 Ah Eve and this is what I've bought: https://eu.nkon.nl/rechargeable/lif...105-prismatic-105ah-105a-lifepo4-a-grade.html

Bought 16, of which 8 were in the clear. The other 8 were not. As said, no test report was provided and no manifest of what is in the box, for warranty purposes. I would have expected a sheet of paper stating that 8+8 cells with code such and such were sold to "marksman", but no, there was no such thing.

LE: in the end I do not really care about grade, but I want to receive what I paid for, in the condition described. Steve_S is right about trying to save here and there. Should have bought GWL's own cells, 100 "real, tested" amp-hours.

 

[houseofancients]

There is only one item advertised as grade A 105 Ah Eve and this is what I've bought: https://eu.nkon.nl/rechargeable/lif...105-prismatic-105ah-105a-lifepo4-a-grade.html

Bought 16, of which 8 were in the clear. The other 8 were not. As said, no test report was provided and no manifest of what is in the box, for warranty purposes. I would have expected a sheet of paper stating that 8+8 cells with code such and such were sold to "marksman", but no, there was no such thing.

Did you ask for a test report ?
I very sure you got a receipt stating how many cells your ordered, your order and ref number.

 

[Pi Curio]

Initially I wanted to order 100 Ah cells from GWL. They make their own (well, actually the cells are made in Chinese factories as far as I understand) and they test them and provide test reports. The price difference was, well, significant and I've read good reviews regarding nkon.

Always an option.

 

[marksman]

Did you ask for a test report ?
I very sure you got a receipt stating how many cells your ordered, your order and ref number.

Yes, that is the only thing I've got: receipt stating 16 cells, order, ref no. No, I did not ask for a test report, but I would expect to find a manifest stating that cell number 1, QR code whatever - cell number 16, QR code whatever were sold.

LE: I'm not saying that Nkon willingly did this (reprinting the code), but rather they got duped themselves. But it's the seller's duty to make sure that what they sell is the advertised item in the advertised state. If they got scammed I'm sorry, but it's not me who should foot the bill.

 

[houseofancients]

Yes, that is the only thing I've got: receipt stating 16 cells, order, ref no. No, I did not ask for a test report, but I would expect to find a manifest stating that cell number 1, QR code whatever - cell number 16, QR code whatever were sold.

LE: I'm not saying that Nkon willingly did this (reprinting the code), but rather they got duped themselves. But it's the seller's duty to make sure that what they sell is the advertised item in the advertised state. If they got scammed I'm sorry, but it's not me who should foot the bill.

1. They are a cell seller, not your personal cell administrators.
If you wanted test reports , you should have asked, depending on how long ago you ordered, pretty sure they can still provide it, IF you bought a grade cells

2. They buy direct from EVE, on av. 4 containers a month

3. Before complaining on a forum, the least one can do , is give them time to respond to your inquery

 

[Alkaline]

After the Liitokala disaster I saved some money and ordered 16 Eve 105 (grade A) from nkon.nl hoping that I will avoid any other headache related to quality of the cells.

The cells arrived in two boxes, let's call them Box A and Box B, all around 3.29x V. All QR codes turned out valid on Gobel site and using the Android LifePo4QR reader. I've put Box A through the top balance process using a benchtop power supply, following the top balance tutorial on this forum. It took a week to balance to 3.650 V due to 10 A limitation of the power supply. I've assembled Box A into a battery and things seem good.
I then put Box B through the top balance process and now things started to look weird: as opposed to Box A, the initial charging current started at around 9 A. When Box A was top balacing it started at 9.8-ish A and it took two days to drop to 8 A, which seemed consistent with 105 Ah rating. Now it took just under one hour to get from around 9 A to 7.97 A and under 24 h to drop somewhere in the low 6 A. This does not seem consistent with declared capacity of 105 Ah.
And then I noticed something else: from 8 cells in Box B there is only one with laser etched QR code, all others are stickered. As far as I know Eve uses lasered etched codes only. The cells in Box A all had laser etched QR codes.
So what I suspect is that whoever Nkon bought from sold a batch of doctored cells that pretend to be real Eve 105s while they really could be 90Ks or something else, even 75s, since the physical dimensions are identical between them. The cells looked all new and I didn't notice the QR difference at first due to lighting, late hours and tiredness. I've emailed nkon on the subject and asked to solve this.

I've attached some pictures. In the first picture you can see the Box A while top balancing. When enlarging one can see the QR area is not shiney as there are no stickers there. Better view of this is in the last picture, top is Box A, bottom is Box B, you can see the differences and even spot the single etched QR. Second and third picture show Box B, you can see detail between laser etching and sticker.

LE: there was no test report in the boxes and nothing to identify the cells for warranty purposes.

I want to know what is the appeal of posting after you make a purchase? Did you not know about DIY Solar Forum before buying or did you think you are sooo clever that you will make your purchase and then "Show us" how skilled you are getting deals.

I'm getting tired of reading these posts, don't know to or at this point...

 

[Pi Curio]

1. They are a cell seller, not your personal cell administrators.
If you wanted test reports , you should have asked, depending on how long ago you ordered, pretty sure they can still provide it, IF you bought a grade cells

2. They buy direct from EVE, on av. 4 containers a month

3. Before complaining on a forum, the least one can do , is give them time to respond to your inquery

He wasn't complaining, but rather asking for other people thoughts on his experience thus far. There's a difference.

 

[Alkaline]

Did you ask for a test report ?
I very sure you got a receipt stating how many cells your ordered, your order and ref number.

Very much doubting this guy bought grade A from NKON, however, if he has receipts and proof then NKON needs to respond.

 

[marksman]

1. They are a cell seller, not your personal cell administrators.
If you wanted test reports , you should have asked, depending on how long ago you ordered, pretty sure they can still provide it, IF you bought a grade cells

2. They buy direct from EVE, on av. 4 containers a month

3. Before complaining on a forum, the least one can do , is give them time to respond to your inquery

You don't get the idea: the code is not what it should be.

LE: I had my doubts on the fact that Eve is using stickered codes.
As said, probably Nkon got duped themselves, this is NOT to say "OMG, Nkon is unreputable seller, beware!".

 

[marksman]

Very much doubting this guy bought grade A from NKON, however, if he has receipts and proof then NKON needs to respond.

Happy?

 

[marksman]

I want to know what is the appeal of posting after you make a purchase? Did you not know about DIY Solar Forum before buying or did you think you are sooo clever that you will make your purchase and then "Show us" how skilled you are getting deals.

I'm getting tired of reading these posts, don't know to or at this point...

You don't get the idea either: the QR code should have been etched, but it's stickered.

LE: the post was NOT an intention to say that Nkon got me scammed, they got scammed themselves.

 

[upnorthandpersonal]

@everyone in this thread: before you shoot OP down, why not look at the claims. Proof of purchase has been posted. If there are issues with cells delivered by NKON, it's good to have an idea of where the issue could be. I have zero loyalty to any vendor - a vendor in my eyes is only good as long as they deliver what was intended.
OP requested to remove the thread because of some of the responses - I would rather not have to do that because this is an interesting topic and could help others.

 

[Steve_S]

@marksman At this point, there really isn't any point in getting more upset over the situation.
If there is a possible financial recourse that's good but realistically, we have seen this happen ohhh so many times and it rarely works out, sometimes there is a partial refund or a credit of some sort. Shipping cells back and forth is just not practical financially for anyone. The best thing to do, is stop aggravating yourself, deal with them (NKon) and see if you can get something but don't freak out over it.

A suggestion for verification purposes. Pick one of the "stickered" cells, and gently peel back the covering, it's really sticky & not too easy. You should see if there is a lasered QR code on the metal top. If you need to clear it, use Rubbing Alcohol or Acetone on a cloth to wipe the glue off.

From this point, assume this is what you have and have to work with them. In all likelihood, they will be ok and give you the 100AH if used moderately and not pushed. A conservative charging profile with a BMS that does Active Balancing is most likely the best option for you ahead. You don't mention what voltage you're building for specifically.
This is what I recommend as a respectable moderate profile with the least issues with runner cells etc.

Divide Values X2 for 12V. Multiply X2 for 48V.
Bulk / Absorb: 27.6V (Absorb for 45 minutes (3.45vpc) (some call this boost)
Equalize: OFF
Float 27.5V (3.437vpc)
MIn Volts: 21.2V (2.650vpc)
Max Volts: 28.6V (3.575vpc)
Rebulk Voltage: 25.6 (3.200vpc)
End Amps/TailCurrent: *1 (Triggers change from Absorb to Float)
(*1): End Amps is calculated: (100AH X 0.05 = 5A or 280AH X 0.05 = 14A.
EndAmps = TailCurrent
Coulumbic Efficiency / Battery Status Meter Efficiency for LFP = 99%.
This gets the bank charged to full with high amps (Constant Current Constant Voltage) and then float (Constant Voltage, Variable Current) tops off so the cells are at 3.437Vpc. I
! Do Not forget to adjust for Voltage Offsets between Actual Voltage @ Battery Terminal & at Solar Controller.

BMS With Active Balancing should be set to start Active Balancing at 3.420V or possibly lower to 3.410 so that the cells can balance out at the top and not affect the charging process.

Very Special NOTE: Floating & Saturating to 3.437vpc, accounts for the Voltage Settling post Charge of any kind which actually brings the cells to just below 3.400Vpc.

I hope this helps, Good Luck

 

[Pi Curio]

@marksman

Please leave this thread open, and as Steve_S said, it's best to give it time and wait for customer support to get back to you and see what they say. I'm hopeful this will be resolved to your satisfaction.

By all accounts, NKON thus far was a reputable business and this likely was a one-off.

Good luck.