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CALB Battery Build - Testing Question

mboehk

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May 18, 2020
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Hello All, I took the plunge on some CALB batteries off Ebay (same seller on AliExpress). They were 72AH Aluminum cased and marked as L135F72F "New - Grade A". They certainly look brand new, not a scratch on them or the posts, but it appears as if small barcode or brand sticker on top was removed, no other barcode was included, but there was a data sheet for the cells. I'm trying to evaluate what I have and seek advice from the more experienced people out there.

My BMS hasn't arrived yet, but the battery voltages as arrived were at 3.280, 3.280, 3.281, and 3.280. I've top balanced all the cells and then ran an approximate 0.2C test using an inverter load carefully monitoring everything. My two meters did not match exactly but one said 70Ah and the other was 72.5Ah when the inverter cut out and left the pack at about 10.95V, so it looks like these batteries are certainly in the range of what they should be.

Ending voltages of the cells were all within 0.02V of each other (actually 3 were nearly identical). I charged them back up a bit so they could "rest" while I wait for my BMS. Voltages are sitting at 3.321, 3.320, 3.320, and 3.320. So as far as I can tell these seem to be new with approx the full capacity and they don't seem to go out of balance much at all.

Are there any other tests I should do? Are these results typical of New, Matched cells?

I'm just trying to get a feel for what I bought because I know I was taking a bit of a risk (although the seller had a 100% rating and comments about how his batteries were matched and full capacity).

Thanks for any wisdom and advice.
Mike
 
Sounds about right to me. Good job.

Generally speaking, I've noticed that brand new cells tend to have slightly more than the nameplate capacity. How did you top balance them?
 
I used the same technique as Will showed in a couple videos - 4 of them in parallel and then charge with a power supply. It was amazing how long that takes . . . I can't imagine what it's like to do 4 - 100ah or 180ah in parallel.

Since they were all within 0.001V of each other on arrival, I think the next time I'd charge them in series up to 80-90% before doing a top balance. My charger is limited at 10A, but doing them in series gives each one 10A instead of just 2.5A each when in parallel.

Once my BMS comes in (slow boat from China) I plan on top balancing them one more time and then connecting them in series again with the BMS, then I'd probably do another capacity test with the BMS in place to see how it performs.
 
I used the same technique as Will showed in a couple videos - 4 of them in parallel and then charge with a power supply. It was amazing how long that takes . . . I can't imagine what it's like to do 4 - 100ah or 180ah in parallel.

So, what did you charge them to and at what current? And, did you happen to note the current at the end? (Or, maybe, how did you decide to stop charging?)
 
but it appears as if small barcode or brand sticker on top was removed
Immediate red flag for me. I would never buy batteries that have had anything removed. This tells me there is something to hide. Did the terminals have the "seals" (stickers) on them when they arrived?


I just ordered 64 CA180 cells for one battery bank, and have orders of 16 pcs, 24 pcs and another 64 pcs on the way. Every single battery has a barcode that describes the exact date of MFG, the battery number for the day (for example, 500 would be the 500th battery on day xx/yy/zzzz).


Toss in some pictures of the bank you built. I'd be interested to see.

Do you have the link to the original listing on aliexpress?
 
Every single battery has a barcode that describes the exact date of MFG, the battery number for the day (for example, 500 would be the 500th battery on day xx/yy/zzzz).
Do you have the means to cross-reference the code scanned in by the QR with actual useful data like that? I've got plenty of laser QR readers about to read any format code, it's interpreting the result that eludes me.
 
Do you have the means to cross-reference the code scanned in by the QR with actual useful data like that? I've got plenty of laser QR readers about to read any format code, it's interpreting the result that eludes me.
Can you send a high-quality picture that I can scan? From what I know the QR is the serial number but in a more condensed format. I may be able to decipher the serial from it.
 
Can you send a high-quality picture that I can scan? From what I know the QR is the serial number but in a more condensed format. I may be able to decipher the serial from it.
I don't have my own batteries yet but maybe someone else can provide photos. I did find a sample LiFePO4 barcode on the internet and it scanned as:
07HCBC1P18K03A8B80000930

So yeah, seems like a serial # or other encoded data. To make any sense of that, we need a means to cross-reference or decode its parts.
 
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