EVE LF280K possible problems?

[DWalker]

Edited to hopefully make more sense.

Hello everyone. I’ve been reading many various posts on here for a few months in trying to learn about building and maintaining Lifepo4 battery cells but this is my first post about anything.
Last October 2022, I bought 8 ‘Eve LF280K’ supposedly A grade (-doubtful?) from ‘Amy Zheng’ at Docan Power. The transaction went well with fast shipping and fast email replies.
I did a good top balance on the cells and configured them as 12V 2P-4S configuration installing them inside an insulated box in my 5th wheel RV using one 200A JBD bms. Prior to the LF280K cells, I’d been using Trojan T-105’s for the last 7 years.
I’m having some problems now after 2 charges with the new 280 cells that I’d like to get some thoughts on from anyone that may be some help in figuring out what’s going on.
The first full charge was up to 14.2 volts, then absorb for two hrs. using a Victron IP22 charger, then I discharged to 10.6V then back to about a 60% SOC to sit. (FWIW, the batteries are in a box in the RV which is stored inside my shop and the battery bank is a constant 55-60 degs. F day and night).
A few weeks after that first full charge, I decided to do another charge on the bank for the heck of it and noticed a high mv spread starting at mid 13 volts. The spread went up to 326mv at 14.0 total bank volts. I stopped the charge there because it was increasing fast and I could see that it was going to hit the HVD so just stopped it.
Stopping the charge at bank voltage of 14.0-14.1V, #1 and #3 cells were low in voltage, just over 3.0V. #2 was roughly 3.6 and #4 was up to about 3.41-3.42V when stopped. It was definitely heading for HVD showing 326mv and moving up fast. I had the balancing set to start at 3.42V but there’s obviously no way it could possibly do anything as fast as the spread was climbing and as big as it was.
I moved some cells around in the bank a couple times and tried charging again but now I get a HVD (set at 13.6V) on cell #4 before the other cells get barely over 3V. I moved the charged voltage down to 13.8V but am having the same problem and it gets worse each attempt.
I’ve changed charger current between 15A and 30A on the IP22 and 18A from solar panels mounted outside the shop but of course all have same results.
I bought an internal resistance tester and checked the cells yesterday, I see 38, 38, 39, 42 and 62, 64, 65, 67 milliohm, the last 4 seems very high considering the specs. sheet show 19 milliohm?
I’m currently doing another top balance now using the 4 lower ir cells to then try using those 4 in a 4s configuration to see what happens, then do the same with the 4 high ir cells.
I’ve sent an email to Amy at Docan Power but I’ve got no response of any kind. I’m thinking since I’m not buying now but asking about a possible problem, I most likely won’t get a response. -I apologize for the length of this.
Any thoughts on what’s happening here?

Thanks, D. Walker

 

[Bud Martin]

Hello everyone. I’ve been reading many various posts on here for a few months in trying to learn about building and maintaining Lifepo4 battery cells but this is my first post about anything.
Last October 2022, I bought 8 ‘Eve LF280K’ supposedly A grade (-doubtful?) from ‘Amy Zheng’ at Docan Power. The transaction went well with fast shipping and fast email replies.
I did a good top balance on the cells and configured them as 12V 2P-4S configuration installing them inside an insulated box in my 5th wheel RV using one 200A JBD bms. Prior to the LF280K cells, I’d been using Trojan T-105’s for the last 7 years.
I’m having some problems now after 2 charges with the new 280 cells that I’d like to get some thoughts on from anyone that may be some help in figuring out what’s going on.
The first full charge was up to 14.2 volts, then absorb for two hrs. using a Victron IP22 charger, then I discharged to 12.6V then back to about a 60% SOC to sit. (FWIW, the batteries are in a box in the RV which is stored inside my shop and the battery bank is a constant 55-60 degs. F day and night).
A few weeks after that first full charge, I decided to do another charge on the bank for the heck of it and noticed a high ma spread starting at mid 13 volts. The spread went up to 326ma at 14.0V. I stopped the charge there because it was increasing fast and I could see that it was going to hit the HVD so I just stopped it.
Stopping the charge at 14.1V, #1 and #3 cells were low in voltage, just over 13 to mid 13V. #2 was roughly 13.6 and #4 was at 14.1 when I stopped it but was definitely heading for a HVD showing 326ma and moving up fast. I had the balancing set at 3.42 but there’s obviously no way it could possibly do anything as fast as the spread was climbing and as big as it was.
I moved some cells around in the bank a couple times and tried charging again but now I get a HVD (set at 14.6) on cell #4 before the other cells get barely over 13V. I moved the charged voltage down to 13.8V but I’m having the same problem and it gets worse each attempt.
I’ve changed charge current between 15 and 30 on the IP22 and 18A from solar panels mounted outside the shop but of course all have same results.
I bought an internal resistance tester and checked the cells yesterday, I see 38, 38, 39, 42 and 62, 64, 65, 67ma., the last 4 seems very high considering the specs. say 21ma?
I’m currently doing another top balance now using the 4 lower ir cells to then try using those 4 in a 4s configuration to see what happens, then do the same with the 4 high ir cells.
I’ve sent an email to Amy at Docan Power but I’ve got no response of any kind. I’m thinking since I’m not buying now but asking about a possible problem, I most likely won’t get a response. -I apologize for the length of this.
Any thoughts on what’s happening here?

Thanks, D. Walker

Some of your descriptions do not make sense.
1) "The spread went up to 326ma at 14.0V." Do you mean 326mV?

2) "I just stopped it. Stopping the charge at 14.1V, #1 and #3 cells were low in voltage, just over 13 to mid 13V. #2 was roughly 13.6 and #4 was at 14.1" Cell Voltage of LiFePO4 is 3.2V nominal, so how can you have 13 ~ 14V on the cells?

3) "I bought an internal resistance tester and checked the cells yesterday, I see 38, 38, 39, 42 and 62, 64, 65, 67ma., the last 4 seems very high considering the specs. say 21ma? Resistance is read in Ohm, not in Amp. What are the milliohm (mΩ) as printed on the cell's stickers?

 

[DWalker]

Some of your descriptions do not make sense.
1) "The spread went up to 326ma at 14.0V." Do you mean 326mV?

2) "I just stopped it. Stopping the charge at 14.1V, #1 and #3 cells were low in voltage, just over 13 to mid 13V. #2 was roughly 13.6 and #4 was at 14.1" Cell Voltage of LiFePO4 is 3.2V nominal, so how can you have 13 ~ 14V on the cells?

3) "I bought an internal resistance tester and checked the cells yesterday, I see 38, 38, 39, 42 and 62, 64, 65, 67ma., the last 4 seems very high considering the specs. say 21ma? Resistance is read in Ohm, not in Amp. What are the milliohm (mΩ) as printed on the cell's stickers?

1; Lol... yes, mV.
2; Total bank voltage and cells mixed up, read 3.3-3.4---3.6 and 4.1 cell voltage.
3; Yes, milliOHMS, not amps. The milliohm for each cell is what's shown on the tape on the cells.
Too many amps, ohms and volts on the brain.

I was wrong abt. the spec. sheet showing 21 milliohm...,it's 19. Makes mine farther away yet.

 

[Bud Martin]

"2; Total bank voltage and cells mixed up, read 3.3-3.4---3.6 and 4.1 cell voltage."
Are you sure it is 4.1V? max is 3.65V, if you go above that you will damage the cell. Are you using Multimeter to read each cell Voltage?

Are you sure it is 21milliohm not 0.21 milliohm? Look at the sticker on the battery or show us the sticker on the battery. 21miiliohm is really bad.

 

[Alkaline]

Did you accidentally set the JBD to lithium Polymer or LION setting and not LFP? Cause this would be the wrong profile.

 

[DWalker]

Did you accidentally set the JBD to lithium Polymer or LION setting and not LFP? Cause this would be the wrong profile.

No, wish that was the problem, it's set correctly.

 

[HRTKD]

Your cells do not appear to be bloated, so that's a good sign.

You may not have good contact between your cell terminals and the large copper bus bar. Be sure that the cells are placed on a flat surface so they are all sitting at the same height. It looks like you have your cells sitting on a piece of carpet.

Are the cell terminal surfaces clean and clear of any obstructions? From the picture, your cell terminals look oxidized. They should be cleaned and treated with an anti-oxidation paste. Also, since you're using bare copper, you really need that paste to ensure there isn't any galvanic corrosion between the dissimilar metals.

Do you have a picture of your battery in the 2p4s configuration?

 

[Zwy]

Edited to hopefully make more sense.

Hello everyone. I’ve been reading many various posts on here for a few months in trying to learn about building and maintaining Lifepo4 battery cells but this is my first post about anything.
Last October 2022, I bought 8 ‘Eve LF280K’ supposedly A grade (-doubtful?) from ‘Amy Zheng’ at Docan Power. The transaction went well with fast shipping and fast email replies.
I did a good top balance on the cells and configured them as 12V 2P-4S configuration installing them inside an insulated box in my 5th wheel RV using one 200A JBD bms. Prior to the LF280K cells, I’d been using Trojan T-105’s for the last 7 years.
I’m having some problems now after 2 charges with the new 280 cells that I’d like to get some thoughts on from anyone that may be some help in figuring out what’s going on.
The first full charge was up to 14.2 volts, then absorb for two hrs. using a Victron IP22 charger, then I discharged to 10.6V then back to about a 60% SOC to sit. (FWIW, the batteries are in a box in the RV which is stored inside my shop and the battery bank is a constant 55-60 degs. F day and night).
A few weeks after that first full charge, I decided to do another charge on the bank for the heck of it and noticed a high mv spread starting at mid 13 volts. The spread went up to 326mv at 14.0 total bank volts. I stopped the charge there because it was increasing fast and I could see that it was going to hit the HVD so just stopped it.
Stopping the charge at bank voltage of 14.0-14.1V, #1 and #3 cells were low in voltage, just over 3.0V. #2 was roughly 3.6 and

#4 was up to about 4.1-4.2V when stopped.

Houston, we have a problem. It should have hit High Cell Voltage Disconnect at 3.65V

The BMS is not doing what it should or it is configured incorrectly.

It was definitely heading for HVD showing 326mv and moving up fast. I had the balancing set to start at 3.42V but there’s obviously no way it could possibly do anything as fast as the spread was climbing and as big as it was.
I moved some cells around in the bank a couple times and tried charging again but now I get a HVD (set at 14.6V) on cell #4 before the other cells get barely over 3V. I moved the charged voltage down to 13.8V but am having the same problem and it gets worse each attempt.
I’ve changed charger current between 15A and 30A on the IP22 and 18A from solar panels mounted outside the shop but of course all have same results.
I bought an internal resistance tester and checked the cells yesterday, I see 38, 38, 39, 42 and 62, 64, 65, 67 milliohm, the last 4 seems very high considering the specs. sheet show 19 milliohm?
I’m currently doing another top balance now using the 4 lower ir cells to then try using those 4 in a 4s configuration to see what happens, then do the same with the 4 high ir cells.
I’ve sent an email to Amy at Docan Power but I’ve got no response of any kind. I’m thinking since I’m not buying now but asking about a possible problem, I most likely won’t get a response. -I apologize for the length of this.
Any thoughts on what’s happening here?

Thanks, D. Walker

 

[Alkaline]

Well then welcome to the 280K is a dud club... anyway I would say get this attach and just leave it:

https://www.amazon.com/Cywhrvzsf-Equalizer-Balancer-Equalization-Capacitor/dp/B09G74WDN5/r

I could go on and and on about the 280K but at this point its? a ?...

So I had to use the 8s versions of these in my old xuba 280N and basen pack other wise they would drift around, some people say NOO you don't need them but I'm telling you it was the only thing that kept them in balance otherwise I would need to rip apart my pack and manually re-balance.

The only ones that did not need this were grade A cells form Luyuan that came with the test report. Those were just well behaving cells that did not give me any problems.

 

[DWalker]

Your cells do not appear to be bloated, so that's a good sign.

You may not have good contact between your cell terminals and the large copper bus bar. Be sure that the cells are placed on a flat surface so they are all sitting at the same height. It looks like you have your cells sitting on a piece of carpet.

Are the cell terminal surfaces clean and clear of any obstructions? From the picture, your cell terminals look oxidized. They should be cleaned and treated with an anti-oxidation paste. Also, since you're using bare copper, you really need that paste to ensure there isn't any galvanic corrosion between the dissimilar metals.

Do you have a picture of your battery in the 2p4s configuration?

 

[DWalker]

Thanks for the response.
The cells showing now in the picture are just sitting on a shop bench here being top balanced, it's not their normal setting.
The cell terminal bases were (and will be again) treated with a light coat of No-Ox paste. I originally trued the buss bars with my milling machine before installing them along with the NoOx coating.
That's also one of the first things I looked for when taking the box apart to get em out was looking for bloating. There really isn't any more bloat now than when I first got them.
Attached is a pic of then in the rv as I started taking them out.

I should add... the BMS and adtl. wiring is messy looking from moving cells around a couple different times when testing.

 

[Bud Martin]

BTW, did you ever compare what the Cellmeter-8 Voltage reading on each cell and compared it to your multimeter reading? I have Cellmeter-8 also and they are like 10% off from my calibrated Fluke meters.
I do not believe the 4.1V is the true reading, more like a measurement error.

 

[DWalker]

Houston, we have a problem. It should have hit High Cell Voltage Disconnect at 3.65V

The BMS is not doing what it should or it is configured incorrectly.

Well, another typo if I said anything other than 3.65V, I definately should've proof read my post before postion.
The HVD was set for 3.65 the in the beginning, I then lowered it to 3.6V . That's where it's currently at.

 

[DWalker]

BTW, did you ever compare what the Cellmeter-8 Voltage reading on each cell a and compared it to your multimeter reading? I have Cellmeter-8 also and they are like 10% off from my calibrated Fluke meters.

I had that Cell meter on the T-105's previously so just used it again, but comparing it to my Fluke and even the BMS, it's not anything I'd go by, that's for sure. The BMS and Fluke are actually right together. I have a Victron BMV 712 in there also, it's also always off a bit.

 

[HRTKD]

The battery, as installed in the RV, looks good. Nice setup. The three balance/monitor leads threw me off at first. Two I understand, but why three?

When you did the initial top balance, what voltage did you take the cells to?

 

[HighTechLab]

Thanks for the response.
The cells showing now in the picture are just sitting on a shop bench here being top balanced, it's not their normal setting.
The cell terminal bases were (and will be again) treated with a light coat of No-Ox paste. I originally trued the buss bars with my milling machine before installing them along with the NoOx coating.
That's also one of the first things I looked for when taking the box apart to get em out was looking for bloating. There really isn't any more bloat now than when I first got them.
Attached is a pic of then in the rv as I started taking them out.

Sorry for off topic, but what is going on with those shunts!?!? If you are trying to measure current with both shunts they should be in series not in parallel

 

[DWalker]

Houston, we have a problem. It should have hit High Cell Voltage Disconnect at 3.65V

The BMS is not doing what it should or it is configured incorrectly.

3.41 - 3.42.

Sorry for off topic, but what is going on with those shunts!?!? If you are trying to measure current with both shunts they should be in series not in parallel

The Trimetric shunt was mounted prior to the BMV 712. It's a temp. situation because I had the extra bars and the length worked out well for now. The charge current is splitting between a BMV and Trimetric shunt, each just shows half the current in and or out of what it would normally be.
It's a 'situated on the wall' change once and if I get the battery figured out.
I took the Trimetric shunt out on one test to see if that made any difference, it didn't.

 

[HRTKD]

I think what Dexter is saying is that with that Trimetric shunt in place, the BMV-712 is going to be off when it's reporting information.

 

[HighTechLab]

I think what Dexter is saying is that with that Trimetric shunt in place, the BMV-712 is going to be off when it's reporting information.

The charge current is splitting between a BMV and Trimetric shun

Yeah, it would be about half current, but the accuracy would be very questionable. Carry on as you were, not trying to steer this thread off the rails

 

[DWalker]

The battery, as installed in the RV, looks good. Nice setup. The three balance/monitor leads threw me off at first. Two I understand, but why three?

When you did the initial top balance, what voltage did you take the cells to?

The initial top balance I did was to 3.65V per cell. After the first charge, I didn't like the cell spread I saw so I put them back in parallel and re top balanced them but used 3.6V/cell that second time around.
The third set of leads were for a 5A Heltec active balancer that was a complete waste of time (IMO). It's just hanging down behind the box doing nothing. Will be redoing and cleaning up a couple areas after and if I can get this charging problem figured out.

BTW, did you ever compare what the Cellmeter-8 Voltage reading on each cell a and compared it to your multimeter reading? I have Cellmeter-8 also and they are like 10% off from my calibrated Fluke meters.
I do not believe the 4.1V is the true reading, more like a measurement error.

Bud, I don't use the cell meter for anything in particular. It's just there stuck to a plate where I once had a Heltec balancer. I'll come of there when I make room on the wall for shunt and other changes. ---I should've moved some of this stuff before taking pictures, lol.