BLS Battery Store Issue - 176Ah 8 Pack

enough

New Member
Joined
Dec 25, 2020
Messages
24
Based on the recommendation and reviews, I bought my first pack of batteries from BLS battery store. I top balanced, capacity tested, and charged and believe that I have one cell (maybe two) that is not allowing the pack to meet its capacity. Ive been in contact with BLS who is blaming the xiaoxiang bms. They are stating that I have to capacity test the individual cells for me to replace any, but how do I capacity test a 3.2V battery when my only load is a 24V inverter? Any other suggestions on getting this resolved?

Long thread of text, but support conversation below:

Yesterday 15:38

Thank you for extending purchase protection window. I have charged, top balanced, and capacity tested the cells and believe that I have a single low-performing cell. My capacity test totaled 163Ah and when the single cell hit 2.5V, other cells were still at 2.83V or higher. Below are images showing the cells top balanced at 3.512V before the capacity test, the cell voltages just before BMS low voltage cut-off at 2.5V, and the capacity on my shunt meter showing 163Ah when restarted after low voltage cut-off. I am using an overkill 24V 100A BMS, Longwei 30V 10A Variable voltage DC power supply to charge, 300A shunt battery monitor and meter, and a Meterk MK06 multimeter to verify the BMS voltages readings and the shunt meter current readings.
Top Balance.jpgLow Voltage Cell 5.jpgCapacity Test Result.jpg

Yesterday 18:48

HTB1ka_xSa6qK1RjSZFmq6x0PFXaF.jpg

你好,我看到您的测试有一个电池容量不好,这个情况我建议您先对电池组充电,然后对这个低电压的电池再单独充电,然后放电测试,谢谢您,圣诞快乐!
Hello, I see that your test has a bad battery capacity. In this case, I suggest you charge the battery pack first, then charge the low voltage battery separately, and then discharge the test. Thank you, merry Christmas!
Alibaba Translation


17:11

HTB1f58GKwHqK1RjSZFg7617JXXam.png

Thank you for the response. I recharged the battery pack and there is no need to charge the low voltage battery separately. The low voltage cell, cell 5, limited the charging, hitting 3.6V while the remaining cells in the pack were ~3.4V. See image below.
Read

unnamed.png
19:48

HTB1ka_xSa6qK1RjSZFmq6x0PFXaF.jpg

不瞒你说,XIAOXIANG BMS总是这样的情况,我们其它使用别的BMS的客户没有这样的反馈,所以我们还是建议您单独测试细胞,我们很多客户更换了BMS后就没有任何问题,有时候不是电池的问题,是BMS不可靠,不准确,谢谢您
To tell you the truth, this is always the case XIAOXIANG BMS. Other customers who use other BMS do not have such feedback, so we recommend that you test the cells separately, many of our customers do not have any problems after replacing BMS. Sometimes it is not the battery problem, but BMS is unreliable and inaccurate. Thank you
Alibaba Translation


23:00

HTB1f58GKwHqK1RjSZFg7617JXXam.png

Thank you for the response. I have verified the voltage and current data with a Meterk MK06 multimeter
Read


I can assure you I have accurate capacity and voltage measurements
Read


23:06

HTB1ka_xSa6qK1RjSZFmq6x0PFXaF.jpg

明白,您单独测试一下怀疑有问题的细胞,根据我们客户的反馈,xiaoxiang bms的确不太可靠,
I understand. You can test the cells suspected to have problems separately. According to the feedback from our customers, xiaoxiang bms is really not reliable,
Alibaba Translation


23:14

HTB1ka_xSa6qK1RjSZFmq6x0PFXaF.jpg

如果您测试了某个细胞容量不足,或者有缺陷,我们会免费给你更换
If you have tested a cell with insufficient capacity or defects, we will replace it for free.
Alibaba Translation
 

DThames

Photon Sorcerer
Joined
Nov 22, 2019
Messages
1,440
Will did a video on testers like this one. Chargers like the X8 ICharger will charge and discharge cells, reporting capacity.
 

enough

New Member
Joined
Dec 25, 2020
Messages
24
Thanks for the info. I dont think it makes sense for me to buy an X8 ICharger at $150 to justify to BLS that I have a bad cell that cost ~$150.

BLS is continuing to run in circles and after the second capacity test, I think both cells 5 and 7 might be bad:

I do not have the hardware to capacity test individual cells. I have shown that the pack does not have the advertised capacity. If you do not trust my troubleshooting to narrow it down to a single cell, then please replace all 8.
Read






20:11

HTB1ka_xSa6qK1RjSZFmq6x0PFXaF.jpg

你目前的情况不是电池缺陷,是充电不平衡,正常情况下,如果你的BMS具有平衡功能,使用一段时间以后就能平衡好全部的电池,并不是电池本身有质量问题或者容量不足
Your current situation is not battery defect, but unbalanced charging. Under normal circumstances, if your BMS has the balance function, you can balance all the batteries after using it for a period of time, it is not because the battery itself has quality problems or insufficient capacity.
Alibaba Translation


您目前的情况下,电池组的容量是多少呢?
What is the capacity of the battery pack in your current situation?
Alibaba Translation


20:43

HTB1f58GKwHqK1RjSZFg7617JXXam.png

unbalanced charging is not the issue. please see my first picture that shows the cells were top balanced at 3.512V +- .002V. the fourth picture shows that the BMS does balance during charging as well (unsuccessfully with the bad cell)
Read


I attempted another capacity discharge test at only 0.3C and it failed again at 170ah with cell 5 on low voltage. please see the following images:
Read

U0962a021046d42f886631a95e7aeadb86.jpgUd8cef935ec9147ff8c3f169608ed6a8dx.jpg



Read


the pack is 8s1P, 24V 176ah
Read


20:58

HTB1ka_xSa6qK1RjSZFmq6x0PFXaF.jpg

看到了,这个情况您可以尝试一下对细胞5单独充满电
See, in this case, you can try to charge cell 5 alone
Alibaba Translation


21:20

HTB1f58GKwHqK1RjSZFg7617JXXam.png

what would that solve? when I charge cell 5 with the pack it is the first one to hit 3.6v!
Read


see my fourth picture
Read


21:47

HTB1ka_xSa6qK1RjSZFmq6x0PFXaF.jpg

这个电压可能是虚电压,
This voltage may be a virtual voltage,
Alibaba Translation


您尝试一下,单独充放电一次
Try charging and discharging separately
Alibaba Translation


22:11

HTB1f58GKwHqK1RjSZFg7617JXXam.png

The voltages are accurate, they were verified with a multimeter.
 

sajjen

Solar Enthusiast
Joined
Nov 28, 2019
Messages
79
Location
Gothenburg, Sweden
You did cells, not a battery. That is one of the reasons you are getting a better price.

It is entirely possible, I would say even likely, that the cells are just out of balance, not deficient.

When you buy cells, you need to have the equipment to handle cells.

If you want a plug and play solution, buy such a product, not separate components.
 

MisterSandals

Participation Medalist
Joined
Nov 5, 2019
Messages
5,083
Location
Silicon Valley
and charged and believe that I have one cell (maybe two) that is not allowing the pack to meet its capacity.
Have you checked the cell voltages at high and low states of charge?
Is the BMS cutting out on a high cell voltage preventing the other cells from reaching a full charge?

With some numbers we can see how far out of line the cell capacity(s) are (roughly).
 

enough

New Member
Joined
Dec 25, 2020
Messages
24
You did cells, not a battery. That is one of the reasons you are getting a better price.

It is entirely possible, I would say even likely, that the cells are just out of balance, not deficient.

When you buy cells, you need to have the equipment to handle cells.

If you want a plug and play solution, buy such a product, not separate components.

I don't think you read the second sentence of my original post. Cells were top balanced, charged to 3.6V in parallel and then left in parallel for 12 hours. If you see the first picture I attached, you see that they ended up at 3.512 +- 0.002V.

Also, ignoring the top balance, how can balancing be the issue when the cell that cuts out on low voltage for the discharge is the same cell that cuts off on high voltage on the charge?

Have you checked the cell voltages at high and low states of charge?
Is the BMS cutting out on a high cell voltage preventing the other cells from reaching a full charge?

With some numbers we can see how far out of line the cell capacity(s) are (roughly).

Are the pictures I inserted visible? I attached images showing the top balance, and cell voltages after the first discharge, first recharge and second discharge. Yes, the same cell that cuts off on low voltage, preventing a full discharge is the same cell that cuts off on high voltage, preventing a full charge.

Thanks for the feedback - if there is something that I can do to fix this, obviously that would be the best way to go.
 
Last edited:

enough

New Member
Joined
Dec 25, 2020
Messages
24
Post to share the pictures again.

Initial top balance:
Top Balance.jpg

First discharge:
Low Voltage Cell 5.jpg

First Recharge:
unnamed (1).png

Second Discharge:
U0962a021046d42f886631a95e7aeadb86.jpg

Second recharge is ongoing.
 

Cdkipp

Solar Addict
Joined
Jul 29, 2020
Messages
1,404
I find this quite convincing you have a weak cell. Are they specifically saying that the BMS is pulling down the cell in the 5 position? You could always reposition them and rerun. Seems they are arguing that since you cannot capacity test a single cell then they are unable to confirm that the cell is performing under stated Ah. I understand the point but that is a bit of a chickenshit---jack you around-type of response. I think something like the Icharger x8 will serve you well not only in this situation but further down the road so the cost may be justified. I have had a pack now for 6 years for my fulltime RV and you do end up taking it all apart and rebalancing every now and then for various reasons and want a piece of equipment that will allow you to see exactly what is happening. Isn't BLS the store where Will just had the problem? I would specifically mention to them that you are on Will's board and we are watching to see how this is handled. I also understood BLS to have a good rep. I was willing to overlook the situation on Will's recent cell purchase since they stepped in so fast to correct it. However, this now seems like a strike 2 within a month and this isn't baseball. This video gives you a feel for what the Icharger8 can do.
 

MisterSandals

Participation Medalist
Joined
Nov 5, 2019
Messages
5,083
Location
Silicon Valley
Your pix were burried in quoted text. I see them now, did not read conversation earlier (bordering on TL;DR and my ADD flaring up. (Sorry))

Yep, cell 5 looks like its lower capacity the the rest. Cell 7 not so good either.
So the capacity you squeezed out was 91.41ah? But measured only thru the BMS?
Ah, ok i see the 163ah from the shunt. That looks convincing enough (to me) with all the other data and pics.
 

enough

New Member
Joined
Dec 25, 2020
Messages
24
Thanks for the link and feedback, glad to know I’m not crazy haha

Charging went as expected82FCD24C-BB07-42FE-8073-E9D20F223085.png
 

enough

New Member
Joined
Dec 25, 2020
Messages
24
So to follow-up. I initiated a dispute and was unable to get any refund or replacement from alibaba express or BLS. BLS continued to state faulty BMS and insufficient balancing. Ali stated that my evidence was insufficient.
 

Cdkipp

Solar Addict
Joined
Jul 29, 2020
Messages
1,404
Well, your evidence was plenty sufficient. BLS is now on my no-buy list.
 

Just John

Photon Sorcerer
Joined
Aug 15, 2020
Messages
2,442
I think to replace two bad cells, I would invest the $30 in a cell tester. Too bad you can't charge them a cell testing fee.
 

Gazoo

Dumb Dumb
Joined
May 12, 2020
Messages
2,810
Location
Texas
So to follow-up. I initiated a dispute and was unable to get any refund or replacement from alibaba express or BLS. BLS continued to state faulty BMS and insufficient balancing. Ali stated that my evidence was insufficient.
That's a shame since you have compared the voltages of your BMS with the voltage of your multimeter, Are you measuring the voltage right at the cell terminals with your multimeter? I am not talking about the busbars or screws, but right at the terminal. Assuming you are, and your cells terminals are clean, then I would file a dispute with your CC company.

Your delta at the bottom is similar to mine, just under .500mv's. My delta at the top has been as low as 80mv's with my eight 280hr cells. Going by your photos you have two weak cells. BTW, I have that same BMS and personally I believe it's reliable.
 

100kwh-hunter

Solar Enthusiast
Joined
Nov 29, 2020
Messages
105
I do not know this bms charger/tester.
But here is my point of view/thought:
I tend to agree with BLS, i dont have any mans to offend you or to insult you, please also bear in mind that English is NOT my native language.

As with any cell thus not a battery you must charge the cells up to there max voltage, all together or all at ones.
If you use a bms of any kind, it will start in its own parameters at a certain point(v) its balancing program.
Withs means (depends on a active or a passive balance) it will stop charging a full cell and slower charging a half full cell to avoid the full cell to get to much V.
Or it is burning off to much V from the full cell or replacing a certain amount to a low V cell, ect.

The "balancing act" no matter witch one: it can take up months of time to complete.....litarly months!.
Some big powerwalls(100kwh+) with Nissan leaf cells just slap/stack together will take years, without any preparation like cell level top balancing.

Before or in the mean time or after you can test with the 4 wire Kelvin method the internal resistance yourself.

If all the cells are top charged (charge them all in one go, parallel and let them balance before capacity testing)and balanced incl ir tested then you can figure out your packs before assemblage a battery.

With best regards Igor
 

Cdkipp

Solar Addict
Joined
Jul 29, 2020
Messages
1,404
I do not know this bms charger/tester.
But here is my point of view/thought:
I tend to agree with BLS, i dont have any mans to offend you or to insult you, please also bear in mind that English is NOT my native language.

As with any cell thus not a battery you must charge the cells up to there max voltage, all together or all at ones.
If you use a bms of any kind, it will start in its own parameters at a certain point(v) its balancing program.
Withs means (depends on a active or a passive balance) it will stop charging a full cell and slower charging a half full cell to avoid the full cell to get to much V.
Or it is burning off to much V from the full cell or replacing a certain amount to a low V cell, ect.

The "balancing act" no matter witch one: it can take up months of time to complete.....litarly months!.


Before or in the mean time or after you can test with the 4 wire Kelvin method the internal resistance yourself.

If all the cells are top charged (charge them all in one go, parallel and let them balance before capacity testing)and balanced incl ir tested then you can figure out your packs before assemblage a battery.

With best regards Igor
Well then I am sure you will be happy with the BLS batteries you just impulsed purchased.
 

100kwh-hunter

Solar Enthusiast
Joined
Nov 29, 2020
Messages
105
They sell a lot of cells, i suspect they know what they are doing...
Oke there sites/partners are not tracable...
And like most "blue"lifepo4 cells they are second handed...I dare to state 99%!!!!is second handed aand a year old!!!!
If new you would be paying double
Again do you know how to manage them properly???I guess not...
After buying 5x 13 kwh...They always sold what they advertised....
Knowing ir and fabrick specifications, they are good.
You did you homework? i did.


75% depends on how you tread the cells, OP did not know obviously.....
BLS sells 100.000 cells a month, for the last 20 years.....and just in one message they are all bad....
If the cells were properly! handled! from the beginning! and they where really bad, BLS would have replaced them before you can fart....
No i dont make a impulse purchase.....I do my homework about a lot of things....
Incl how to tread the cells and the seller.
Again, dont waste time with a bms to get your pack ready,(There are a number of rules for lifepo and other chemistry...)....it will take years, if you dont fudge them up...prove me wrong!
Good luck and just buy the cheapest if you know for what to look out for and how to tread them....
 

Cdkipp

Solar Addict
Joined
Jul 29, 2020
Messages
1,404
Well these clearly were defective cells if you read the results. This was the second incident as they also sent Will Prowse mislabeled LTO cells. If you send Will Prowse bad stuff things are really screwed up.
 
Top