EVE Specification Code "66", is this 280Ah ?

lexio

feel the balance 3.65
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You are learning a lesson that many people have learned:
1. unbalanced cells
2. charged in series
3. without automated protection
4. may look fine at mid SOC
5. but can go screwy rapidly towards the top or bottom


Some notes for the future.
Your charger didn't react because it probably did not know it needed to. A BMS handles cell level safety, a charger is only aware of pack level voltage, and because your pack has not been balanced pack level voltage will not necessarily reflect cell level voltage (as you experienced). Even with a balanced pack, pack level voltage should not be assumed to be an accurate proxy for cell level voltage. As an example cell voltages of [4V + 3.5V + 3.5V + 3.5V] /4 = 3.625V avg, which is a safe voltage as far as the charger is concerned, since it can only see the total pack level, not individual cell voltages.

As a general pointer, patience and/or extreme attentiveness are the best approach to top balancing. Most of the issues we see here, come from people trying to speed the process up (either by an unprotected series charge or setting the voltage too high and not actively monitoring with a parallel charge).

The good news is, you caught it at 3.9, and a single cell exceeding 3.9 for a few minutes is probably not a huge deal in the realm of things.

From what I have observed, people that follow these three guidelines (and one honorable mention) have to work a lot harder to damage a cell:
  1. Never charge in series without a working BMS
  2. Never set your power supply above ~3.65 or 3.70 when charging in parallel
  3. Know how your power supply works, and set the voltage before connecting the cells
  • Honorable mention: Be present and attentive when charging in parallel above ~3.45 or 3.5 or so
Follow these 3 (well 4) guidelines and chances of damage are very small. More experienced or less cautious folks will sometimes not follow #2, I'm not saying its wrong to do so, just that it increases risk that could be easily avoided. What I am saying is for everyone, but especially beginners, following these guidelines significantly reduces the chances of error or damage (at the expense of a little extra time and effort). My anecdotal observation is that almost every problem with top balancing I have seen on the forum has been partially or fully explained by one of these 4 factors.
calibrate your tools. my calibration point was the voltage reading from my BMS. my bench-power supply was 0.10v volt off
 
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Dzl

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That is great news, not too many people lately have been getting a pack level capacity => 280

Congrats Mariner62. The LF280N image looks like none of the tests made it to 280Ah. They are about 270Ah to 280Ah and that was a brand new cell.
The mark just to the left of the low point of the voltage curves is 275Ah, looks to me like all tests are >280 (which they should be since that is what EVE explicitly guarantees for new Grade-A)
 

Mariner62

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The graphs are for visual comparison only. The 282Ah I measured is an integration of the average current in 1 minute intervals over the ~10 hour test. Dependent on the accuracy of the BMS/shunt and my clock 🤣
 

ArthurEld

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That is great news, not too many people lately have been getting a pack level capacity => 280


The mark just to the left of the low point of the voltage curves is 275Ah, looks to me like all tests are >280 (which they should be since that is what EVE explicitly guarantees for new Grade-A)
I don't know what I was seeing. 👿
You are definitely right Dzl.

I have to stop rapid posting because I don't have a rapid brain

And I knew your test was separate Mariner.
 

Mariner62

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For completeness, here is the first full charge of the new bank. It's interesting how the cell voltages waver around, a bit like the discharge cycle. There must be some physical reason for that in these cells. Its almost like a "signature".

The charge settings on the BMS include balancing at 3.45V and above, while the End-of-Charge is called when the first cell reaches 3.58V. Is that really enough balancing "time"? Those voltages happen quite quickly.

I like the way the combination of the REC BMS and Victron Cerbo GX control the Inverter/Charger to manage the end-of-charge nicely, ramping down the current and controlling the voltage. All well and good, but my future boat system needs to also manage a powerful alternator and Mastervolt charger, neither of which talk Victron's language. Looking forward to that challenge.

For now, I've tested both my AGM and LFP Batteries in the test system and the next step is to hook them up as a hybrid bank and continue to investigate ...


LF280 Charge Test.jpg
 

stxShadow

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The one thing that continues to perplex me is why the charge was not truncated when the BMS raised the out-of-balance alarm. I have the REC BMS which is integrated with the Victron Cerbo GX via CAN Bus. I thought that this architecture should provide a means to truncate charging based on cell out of balance rather than just pack voltage. Could I be mistaken? I'm really hoping that the problem is that I have just not configured it correctly. I chose the REC BMS because of the CAN BUS integration so that I don't have to rely on HV disconnect to truncate charge. I wanted HV disconnect to be used in an error condition only rather than for
Victron uses DVCC to comunicate the charge and discharge currents to the chargers. Is DVCC enabled at your setup ? I use "SimpBMS" and a Cerbo. My Setup stops charging in any error condition -> i checked this more than one time.

Jens

Ah .... just saw in an older post that you use DVCC ...... do you see the charge and discharge limits in the VRM -> advanced tab ?
 
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Mariner62

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Victron uses DVCC to comunicate the charge and discharge currents to the chargers. Is DVCC enabled at your setup ? I use "SimpBMS" and a Cerbo. My Setup stops charging in any error condition -> i checked this more than one time.

Jens

Ah .... just saw in an older post that you use DVCC ...... do you see the charge and discharge limits in the VRM -> advanced tab ?
Hi Jens,
You are correct, the magic happens with DVCC enabled on the Cerbo! The BMS sends voltage/current limits for charging and a current limit for discharging. The Cerbo uses these to control the Victron inverter charge/discharge behaviour. I believe it will also control the Victron MPPT, but I don't have one of these to test here at home.

My next challenge is that I also need to control the end-of-charge behaviour of my Mastervolt 110A alternator and Mastervolt 100A charger on my boat.

i think I need to use the end-of-charge optoisolator output to disable the alternator field and also trigger a contactor to disconnect the 100A charger. Still thinking that through.
🤔
 

stxShadow

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Yes it controls even the MPPTs. I have a fairly big setup: 4 x MP2 5000 with 4 MMPT and 2 Fronius Inverters to power my House. I would like to change from Tesla Model S packs to Lifepo4 for security reasons. So your Thread is quite interresting for me :D

Jens
 

Mariner62

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Yes it controls even the MPPTs. I have a fairly big setup: 4 x MP2 5000 with 4 MMPT and 2 Fronius Inverters to power my House. I would like to change from Tesla Model S packs to Lifepo4 for security reasons. So your Thread is quite interresting for me :D

Jens
That's interesting. At home I have a Fronius Symo 3Phase grid connected inverter with 12KW of panels. I have been trying to work out a way to use the LiFePO4 cells as a battery to store the excess during the day for use in the evening and overnight.
I have not been able to come up with an architecture to do this. To make economic sense the battery augmentation needs to cost less than $10KAUD. I can't see any way to do that. I could use an AC coupled Quattro, but I would need 3 of them so the cost is already more than 10k.
 

stxShadow

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I don't know how it is in Australia. Here in Germany we have "phase compensating" meters. That means: if you feed in 1 kW on the first phase and use 500 watts on each of the other phases the meter reads zero (no payment). Knowing that you can simply start with one MP2 / Quattro, connect it to one phase and let it charge your battery. You also need a Victron Grid meter like EM340 and a GX device (Venus, ColorGX or Cerbo).
The GX reads the used power on the gridmeter and calculates how much power i can either store or has to produce on L1 to compensate L2 and L3. It does that until it reaches its full charging power or inverter power. The victron input is bidirectional for this purpose.

If it is similar in Australia it should be no problem to setup a single phase system and compensate the others.

Hope it helps

Jens
 

Mariner62

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I don't know how it is in Australia. Here in Germany we have "phase compensating" meters. That means: if you feed in 1 kW on the first phase and use 500 watts on each of the other phases the meter reads zero (no payment). Knowing that you can simply start with one MP2 / Quattro, connect it to one phase and let it charge your battery. You also need a Victron Grid meter like EM340 and a GX device (Venus, ColorGX or Cerbo).
The GX reads the used power on the gridmeter and calculates how much power i can either store or has to produce on L1 to compensate L2 and L3. It does that until it reaches its full charging power or inverter power. The victron input is bidirectional for this purpose.

If it is similar in Australia it should be no problem to setup a single phase system and compensate the others.

Hope it helps

Jens
Jens,
Thank you very much for that information. I have done some more research, and I believe that the phase compensating approach is also used in Australia. It seems I can use a EM24, Cerbo GX and a Multiplus/quattro as you suggest. This is great news. I should be able to keep my Fronius smartmeter to feed Solar Web, and use the Cerbo/Em24 to feed VRM. I'm going to do some analysis from my Fronius data over the last few years, and work out a good battery size to make best use of the energy generated, and create minimal feed-in. The most economic solution seems to be using the total energy I generate. There may be value in recharging the battery from the grid when power is cheap too.

Thanks for the thread creep :)
 

stxShadow

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You are welcome .....

Coming back to your thread: is the graph above from VRM ? Why do you think the voltages are going up after cutting off charge current ? I've never seen this before. REC-BMS seems to do a quite good job. I was looking for batrium but that would serve my needs too. I ordered 16 cells a few weeks ago an think of ordering 80 more if everything goes well. Is RECBMS able to balance even a big pack ?

Sorry for my english ..... i'm not a native speaker :(

CU

Jens
 

Mariner62

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You are welcome .....

Coming back to your thread: is the graph above from VRM ? Why do you think the voltages are going up after cutting off charge current ? I've never seen this before. REC-BMS seems to do a quite good job. I was looking for batrium but that would serve my needs too. I ordered 16 cells a few weeks ago an think of ordering 80 more if everything goes well. Is RECBMS able to balance even a big pack ?

Sorry for my english ..... i'm not a native speaker :(

CU

Jens
Hi Jens,
Your English is just fine, no problem.
Yes, the graph is from VRM. The charging current (orange line) 'ramps' down rather than drops vertically to zero. So what you see is the voltage continue to rise as the current falls, then when the current finally gets to zero the voltage stops increasing and starts to fall. It's a well controlled process by the BMS to stop charging and ensure that the cell voltage reaches the target, but does not overshoot.

I am very impressed with this BMS. The 16-channel version will balance (passive) up to 16 serial cells. If you have a very large number of cells then the REC products allow you to build a master-slave system where you can have multiple slave BMS balancing a number of cell sub-packs, which are connected to a single master BMS which communicates with the rest of the system. You should look at the REC website for details.
 

MrPhoton

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I received 4x cells for my test system today, well packaged, all in good condition and reading 3.294V exactly. They appear to be EVE cells, and I've had a look at the EVE specification Rev A on this site to interpret the QR code.
The specification indicates that "Specification Code: 71" is a 280Ah cell. However my cells show "Specification Code: 66" on their QR labels.
Does anyone know what this means?

In case anyone is interested, these are the codes on my cells, interpreted according to the EVE Specification Rev A Attached.
Next step charge, top balance, build the pack and capacity test :)

EVE LFP Cells​

Arrived 7/1/2021

Voltages on Arrival: All Cells 3.294V exactly.

QR Codes

Cell
No.​
Serial Number​
Date Code​
Vendor Code​
Product Code​
Battery Code​
Specification Code​
Tracking Code​
Factory Address Code
1​
3570​
A5M​
02Y​
C​
B​
66​
722700​
J: Jingmen
2​
1867​
A3P​
02Y​
C​
B​
66​
713100​
J: Jingmen
3​
3655​
A63​
02Y​
C​
B​
66​
714400​
J: Jingmen
4​
1867​
A3P​
02Y​
C​
B​
66​
713100​
J: Jingmen
Codes:
Serial Numbers: Same specification cells produced on same day have the same serial numbers.
Date Code is Production Date: [A = 2020] [3=March/5=May/6=June] [3=3rd/M=22nd/P=25th/R=27th]
Vendor Code: 02Y = EVE.
Product Type Code: C= Single Cell.
Battery Type Code: B = Lithium Iron Phosphate
Specification Code: 66 = ???Ah (I know 71 = 280Ah from the Eve Spec).
Tracking Code: Factory production line and work order codes.
Factory Address Code: J = Jingmen, H = Huizhou.

Some Pics.
View attachment 32328

View attachment 32329
View attachment 32330
Curious if anyone ever fully decoded the Manufacturing Date block for EVE stock?
 

Stepandwolf

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Curious if anyone ever fully decoded the Manufacturing Date block for EVE stock?
I tend to agree with his deciphering done in the beginning of this.

If you look at the LF280N data sheet, it shows the production data sample: "87C: Production date code, July 12, 2018". So batteries with date code 8 are 2018. Batteries with "9" date code are 2019, and batteries with "A" date code are 2020.

In the LF280K data sheet. It too explain's EVE's date code. In that example, the date code is A99. A99 is September 8, 2020. Further proof that date code "A" is 2020.

I haven't seen anything firm for 2021, but I saw people reporting date code "B" which should be 2021.

Basen is telling me EVE was out of batteries, therefore there are no 2020 batteries being shipped and insists my ACD-ACG cells were made this year.

"EVE 280AH has been out of stock since March this year, so the price of EVE280ah has directly increased from $82 to $95-$120 now. Therefore, these batteries cannot be from last year or earlier at all. As we all know, this battery is very popular, and we cannot have the previous inventory"

Not sure if it is just her English, but the ending part where she says "we cannot have the previous inventory". I believe Basen didn't have "old stock", but that doesn't mean that EVE or whoever didn't recently sell them 2020 batteries.
 

Gazoo

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If you look at the LF280N data sheet, it shows the production data sample: "87C: Production date code, July 12, 2018". So batteries with date code 8 are 2018. Batteries with "9" date code are 2019, and batteries with "A" date code are 2020.
I noticed that too and it has confused me because I thought LF280N's were manufactured after the LF280's. The date of the spec sheet notes: Effective Date:2019-12-22 and states "New Release Version A". And the specification code is 71.

I am going to attach the spec sheet for the LF280L. Look at the date code and you will see the date code example does not match the date code on the QR label. I think EVE is throwing us a few curve balls.

Edit: I forgot to attach the spec sheet. Here it is.
 

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Stepandwolf

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I noticed that too and it has confused me because I thought LF280N's were manufactured after the LF280's. The date of the spec sheet notes: Effective Date:2019-12-22 and states "New Release Version A". And the specification code is 71.

I am going to attach the spec sheet for the LF280L. Look at the date code and you will see the date code example does not match the date code on the QR label. I think EVE is throwing us a few curve balls.

Edit: I forgot to attach the spec sheet. Here it is.
I think the LF280N spec sheet is flawed. I think they simply screwed up on the date code example. You will notice the actual sample QR code shows a date of A99 which would be 2020 and that would be appropriate for a 2020 designed battery. They used the same sample S/N on the LF280N. The descriptive part where it says 87C is straight from the LF280N sheet. Both said 87C which tells me they cut and pasted part of the spec sheet. 87C was actually used in their 2018 example for the LF280N. The example manufacture date Septemper (sic) 08, 2000 came from the LF280K product sheet. So they cut and pasted part of the N and K datasheets.
 

MrPhoton

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Feel free to inquire with EVE directly as well. I did but have not received a reply yet.


NOTING: Someone poked fun at my reference to an EVE auditor a few days back. Well here it is.

eve-email-1.JPG
 

Stepandwolf

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Feel free to inquire with EVE directly as well. I did but have not received a reply yet.


NOTING: Someone poked fun at my reference to an EVE auditor a few days back. Well here it is.

View attachment 62607
I wasn't the one poking fun, in fact I wanted to try like you did and was hoping to get the information as well.

I have emailed EVE Energy NA twice, no answer. I tried calling them, but I never remember until they are closed for the day. Frankly, with one email I mentioned I was trying to get info on the production of LF280. With a different email I wrote them as a buyer.

The "audit" says it is for misconduct which isn't the case here.

I mentioned in another thread that EVE USA has the LF280 (no suffix) on their site for sale. That could just be old as they aren't offering or discussing the L, K, or N.

Hopefully we can get "authentic" information on the last manufactured date, or if in fact EVE has dribbled them out.
 

mizermizer

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My first post. Been reading this forum and learning for some time now. Invaluable!

I too was trying to decipher my QR label - which led me to this thread. Attached a photo of the QR label from Eve cells I recently purchased on Ali Express (Sanben Global Battery Store). The date code is B32 - so I take that to mean 2021 March 2.

By the way, these cells indeed appear to be, as advertised by the seller, brand spanking new. The whole pack of 8 are perfectly flat (no bulging at all), and very well matched from what I can tell. They were also seemingly at exactly the same state of charge upon arrival, and almost perfect balanced - as I found out while top balancing them myself. I'm in the middle of a capacity test - I can only pull 5 amps so the test is a two day test - but that's okay. I have high hopes to see the full 280.
 

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