need help to ID a battery cell

chadjones99

chadjones LLC
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Arizona & Coloardo
Hello, So I'll try and make this short as I can. I bought a cloud energy 300 AH battery and tested it from 100 SOC charged down to 4% SOC which was 10.5 volt cut off on my inverter using a Victron shunt to measure power out. I pulled 283 AH out. leaving me 17 AH short now I might have gotten 290 ish if I ran it down on my DC loads to the 10-volt BMS cut-off but did not want to .
So I figured a brand new battery should have pulled the full 300 Ah. So today I opened up the battery ( metal case hand lid that was screwed on so easy to do ) and I was expecting 4 cells , but found it has 8. I'm guess 8 x 150 AH cells ? funny the BMS balance leads only had 4 , connected to long sections of bus bar ( multiple cells per lead ) instead of a 8S balancers. So I checked each cell and this is what I found the voltage to be (the battery is at 90% SOC during this )
3.35 , 3.35 , 3.36 ,3.36,3.35,3.35,3.36,3.36 I take it that is pretty well balanced. I figured maybe it was out of balance causing the lower AH reading. so I took picture of the QR code on the cells but none of the websites I found can identify them
the QR code is : 00P-CB-A6N01-L02HB-CP000-1122
can anyone tell me about these other than it looks to me like they were made: Production Date:23/Dec/2021
I'm looking to cell if they are used cells or grade B or what manufacture. or capacity, I'm guess 150 AH if the total pack is sold as a 300 AH battery
Also looking to find out can I piggie back on the balance leads and put an active balancer on it. i see that there is no threaded holes as the bus bars are welded on and not bolted
see attached pictures
 

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Hello, So I'll try and make this short as I can. I bought a cloud energy 300 AH battery and tested it from 100 SOC charged down to 4% SOC which was 10.5 volt cut off on my inverter using a Victron shunt to measure power out. I pulled 283 AH out. leaving me 17 AH short now I might have gotten 290 ish if I ran it down on my DC loads to the 10-volt BMS cut-off but did not want to .

Can't help with ident.

Since you're getting 283/300/(100%-4%) = 98.3% rated, I would not assume they are used at all.

They may very well likely be non-EV grade cells that barely meet or possibly fall slightly short of rated capacity.

Did you charge to the parameters specified by the battery spec?

So I figured a brand new battery should have pulled the full 300 Ah. So today I opened up the battery ( metal case hand lid that was screwed on so easy to do ) and I was expecting 4 cells , but found it has 8. I'm guess 8 x 150 AH cells ?

Probably

funny the BMS balance leads only had 4

Not funny at all. Completely normal. The two parallel cells behave as a single cell in all meaningful ways. As you discovered, measuring the parallel cells will yield identical voltages... because they must.

connected to long sections of bus bar ( multiple cells per lead ) instead of a 8S balancers. So I checked each cell and this is what I found the voltage to be (the battery is at 90% SOC during this )
3.35 , 3.35 , 3.36 ,3.36,3.35,3.35,3.36,3.36 I take it that is pretty well balanced. I figured maybe it was out of balance causing the lower AH reading.

"balance" refers to state of charge, not voltage. Voltage correlates to balance in the upper leg of the voltage curve. If those voltages (you need only measure the four cell groups) stay close in the 3.40-3.65V range, then you can say they're balanced.


so I took picture of the QR code on the cells but none of the websites I found can identify them
the QR code is : 00P-CB-A6N01-L02HB-CP000-1122
can anyone tell me about these other than it looks to me like they were made: Production Date:23/Dec/2021
I'm looking to cell if they are used cells or grade B or what manufacture. or capacity, I'm guess 150 AH if the total pack is sold as a 300 AH battery

Probably a good guess.

Also looking to find out can I piggie back on the balance leads and put an active balancer on it.

Bad idea. If you put an active balancer on it, and you have not shown any reason to do so, you want the active balancer to have its own leads.

i see that there is no threaded holes as the bus bars are welded on and not bolted
see attached pictures

Recommend you charge to the upper limit of the prescribed voltage range, hold that voltage until the charge current drops to 15A and then re-test down to 9.5V allowing the BMS to cut off the discharge.

You're basically trying to make a claim that the battery does not meet capacity while not actually testing the battery's capacity.
 
You're basically trying to make a claim that the battery does not meet capacity while not actually testing the battery's capacity.
sunshine_eggo : "balance" refers to the state of charge, not voltage. Voltage correlates to balance in the upper leg
I disagree, but admit I'm not an expert on this. meaning no matter where you are and it doesn't have to be the upper range all your cells should be close to the same, a balancer looks for a high cell

Good info and thanks for responding, the statement that they are not EV-rated makes sense. I just figures a "NEW" cell should at least pull full cap when new.
Im not making a claim that they are not 300 AH rated ( as a set ) Thats why I made a point to detail the info that I only pulled down to 10.5 ( inverter cut off ) but with the DC loads on in my RV was still on and by the time I disconnected I was at 10.4 when I disconnect and recharged. I was 17 AH short NOT a high deal, being I acknowledged that I could have gotten more out of it, but I doubt 17 more AH and you should never really pull your battery down to the 10.0V ( listed on the spec on this one for BMS cut off ) Why shorten the life any on a none EV grade cell when it is having a hard time as it is reaching full capacity to get a few more AH out to still fail. I mean if I was at 295 AH and hit 10.5 and the inverter shut off then that's a little different store. I did talk to cloud energy and they admitted that if I had pulled down to BMS cut off I would most likely not have gotten more than 295. also and they also stated to not go below 10.5 volts even though 10 volts is BMS cut-off. I thought the BMS,s had a balance lead for each cell not groups of cells. that's all not saying it's bad or good just didn't expect it.
The battery is self looks made well. Another thing I noticed ( and also found on Amazon reviews ) that the 50 amp Anderson plug on the side is not rated for 50 amps . I had read that on a review so I looked at my wiring and found it to have 9 gauge wire ( I know 10 is good for 30 amp but metric wire LOL ) I'm guessing 35 to 40 amps )
I don't plan on using this plug anyway. The main thing I was trying to do was 1) ID the cells 2) being it had a hard time pulling capacity see if there was a fixable reason like cells being out of balance. And I know SOC is not measured by voltage but this is what a balancer looks at. if one cell is HIGH and one s low .... so it doesn't have to be fully charged you can be anywhere in the voltage range for the cell they should all be near the same and it looks like these are close. so that's not the reason.
thanks again for the good info
 
Also unless my math is wrong ( but I did go to school in Florida so maybe ) 4 % is what it says I was short but 4% of 300 ah = 12 ah short but I was 17 AH short at 283 AH... so I'm not sure what happened here. but it didn't reach 300 at 10.4 volts.
 

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So I was closer to 5% short of full capacity? Maybe this is normal Im just not used to testing these batteries I have 5 100 AH batteries , 1 name brand and 4 off brand and they all pulled 100% plus after 1 year use... just saying
 
Can't help with ident.

Since you're getting 283/300/(100%-4%) = 98.3% rated, I would not assume they are used at all.
I went to school in FLA but 100%-4% = 96% ? or did I miss something?
Did you charge to the parameters specified by the battery spec?
Yes I started the test when the Victron said 100% , disconnect from rest of battery bank and started to pull down
"you're basically trying to make a claim that the battery does not meet capacity while not actually testing the battery's capacity.
If I did I might have not explained myself well enough. I meant did not reach full capacity without going below a safe SOC level per cloud energy do not pull down below 10.5 . yes, I could have gotten more AH but in my mind, if you have to go to such a low SOC to get rated capacity the cell should be rated a little higher. meaning 302 or 310 (whatever the next size up is ) so you can pull 300 without risk of damage
 
sunshine_eggo : "balance" refers to the state of charge, not voltage. Voltage correlates to balance in the upper leg
I disagree, but admit I'm not an expert on this. meaning no matter where you are and it doesn't have to be the upper range all your cells should be close to the same, a balancer looks for a high cell

I'm not an expert, but I am 100% certain on this.

Even imbalanced cells will show very tight voltage in the 3.1-3.4V range due to the extreme flatness of the LFP voltage curve.

Conceptually:

There is very little different in voltage between 85% and 88% state of charge. In other words, 3% makes little difference.
There is a huge voltage difference between 97% and 100% state of charge. In other words, 3% makes a huge difference.

I have personally seen as little as 0.1% SoC variation cause a "runner" where a single cell triggers over-voltage protection.

Also unless my math is wrong ( but I did go to school in Florida so maybe ) 4 % is what it says I was short but 4% of 300 ah = 12 ah short but I was 17 AH short at 283 AH... so I'm not sure what happened here. but it didn't reach 300 at 10.4 volts.

Since you're basing your conclusion on the shunt's output, that's the number you should use. On that basis, it says you were 4% short on what you measured. The BMS uses its own circuitry to measure Ah, so it may be different from the shunt.

The shunt reported you used 96% of rated capacity.

You used 283.7Ah per the shunt.

283.7Ah is 96% of the battery's capacity, thus

283.7 / 96% = 295.5Ah.

So your battery has 295.5Ah of available capacity based on the measurement. This is 295.5/300 = 98.5% of the rated capacity.

There's basically a 1.5% error somewhere. It may be the shunt itself.
 
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sunshine_eggo : "balance" refers to the state of charge, not voltage. Voltage correlates to balance in the upper leg
I disagree, but admit I'm not an expert on this. meaning no matter where you are and it doesn't have to be the upper range all your cells should be close to the same, a balancer looks for a high cell
You are wrong. In the middle of the SOC range, voltage is flat. Meaning you could have one cell at 80% and another at 60% but both at nearly the same voltage.

Sunshine_eggo is right. Google Lifepo4 cell voltage chart. That should help give a visual on the cell voltages. It is not linear.
 
You are wrong. In the middle of the SOC range, voltage is flat. Meaning you could have one cell at 80% and another at 60% but both at nearly the same voltage.

Sunshine_eggo is right. Google Lifepo4 cell voltage chart. That should help give a visual on the cell voltages. It is not linear.
I've been wrong before LOL , and admit I'm not an expert on this particular SOC vs voltage of a cell. And will have to concede to you all being right. so I need to force it up to 100 SOC battery cut off to check the balance? I've watched videos of people using cell balancers and they show it balancing at a lower voltage, showing a high cell and the balancer turns on.. so I'm confused cause based on what you all are saying the voltages will be the same mid-state??
I also checked another battery while I was at it , its a 2 year old lynx lifepo4 ( amazon buy ) 100 AH anyway the whole bank was at 90 to 92 SOC when I disconnect them to checked it and got this :
4.40 , 3.39, 3.39 , 3.38 . So it does show some imbalance. so.. this further confuses me . based on what I thought I under stood sunshine_ego to say that they should be the same unless 100 ish SOC ?
 
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I've been wrong before LOL , and admit I'm not an expert on this particular SOC vs voltage of a cell. And will have to concede to you all being right. so I need to force it up to 100 SOC battery cut off to check the balance? I've watched videos of people using cell balancers and they show it balancing at a lower voltage, showing a high cell and the balancer turns on.. so I'm confused cause based on what you all are saying the voltages will be the same mid-state??

Illustrative:

lfp-la.jpg


These are old charts and show charging to 4.2V, so ignore that.

Please see the red line. Note how shallow the slope is between 60 and 80%. It barely changes. Narrow that to just a few %, and it's basically the same number. Move out to the right and look at the steep slope. Voltage will change rapidly with increased charge %. It's in this region that cells get fully charged and when true balance matters.
 
So the #s on the battery i just post that where out a little will be worse closer to 100 soc? So should I check it again next time its charged ?
 
So the #s on the battery i just post that where out a little will be worse closer to 100 soc? So should I check it again next time its charged ?

You can't be sure the battery is balanced until the voltages are typically 3.50V+, and the charge current is below 5A (just be be sure you're fully charged, 15A is more typical).

Once you've charged the battery to the point that it holds all cells at or above 3.50V, the current holding the battery that that level is 5A or less, you can be VERY confident that the battery is truly at 100% charge.

If the battery has a peak charge voltage, use that.

Then discharge and see what you get.
 
You can't be sure the battery is balanced until the voltages are typically 3.50V+, and the charge current is below 5A (just be be sure you're fully charged, 15A is more typical).

Once you've charged the battery to the point that it holds all cells at or above 3.50V, the current holding the battery that that level is 5A or less, you can be VERY confident that the battery is truly at 100% charge.

If the battery has a peak charge voltage, use that.

Then discharge and see what you get.
great info thanks
 
I also checked another battery while I was at it , its a 2 year old lynx lifepo4 ( amazon buy ) 100 AH anyway the whole bank was at 90 to 92 SOC when I disconnect them to checked it and got this :
4.40 , 3.39, 3.39 , 3.38 . So it does show some imbalance. so.. this further confuses me . based on what I thought I under stood sunshine_ego to say that they should be the same unless 100 ish SOC ?
I hope that's a typo on the first cell voltage. Emphasis mine.
 
I don't think this battery is well made as you stated:
1. Soldered cables on the bus-bars ? Really ? It would be somewhat acceptable for a low Ah and low C rate battery, not something this size. OK for balance leads, but not for the current carrying cables.
In general looks somewhat sloppy to me.

2. Bare copper bus bars laser welded on aluminum terminals? Haven't they heard of galvanic corrosion?


Anyways, cells look similar to EVE (more than CATL, GFB or REPT). Maybe the QR code is fake.
 
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Hrm so that would make them 284AH 24v, OP is pulling rated capacity, manufacturer of the pack is not stated real capacity.
 
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