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AliExpress: Beware OYE Store!

Those cheap capacity testers work fine. Keep it to 15 amps (instead of 20) and it won't blow up.

Thanks. I will order one of the capacity testers.

Following advice in another post I cleaned all the battery terminals and busbars. I had unpacked them all in my gloomy garage and hadn't noticed they were really grimy.

I got a 10A bench supply. It would take too long to charge them from flat with this tiddler. So, I ensured all batteries were charged to ~3.15v and then reconnected (in series) to the Sofar ME3000SP. I just put ~4.5kWh into them and no cell ran away (in voltage terms), i.e. charging seems more balanced than before. So, cleaning the terminals seems to have made an improvement but I will need to see how they behave at a higher state of charge tomorrow. (No more charging tonight so I can go to bed and sleep with less worry!) Hopefully I can get all cells to ~3.50v by charging in series with the Sofar unit. After that I'll disassemble the pack again and charge in parallel to 3.65v with the bench supply.

@Watchout - I scanned 15 out of 16 QR codes and they are all P721s. I couldn't find a QR sticker on one of the batteries- possibly it is on the side of the battery but I forgot to check when I had the pack apart.

They may or may not be perfectly safe, although to my thinking they are much more prone to dendrites and thus internal shorts. Cell manufacturers recommend replacing them when 70 to 80% of original capacity for a reason.
I am a newbie so will need to read about dendrites but I understand there are serious risks with old degraded things that have lots of energy stored in them. I plan to relocate these batteries to a waterproof box outside the garage or sell them and swallow the loss. Really I don't like this game any more. It was supposed to be a "fun" project ahead of getting solar panels installed so I could get cheap electric for working from home and crypto mining.
 
Thanks. I will order one of the capacity testers.

Following advice in another post I cleaned all the battery terminals and busbars. I had unpacked them all in my gloomy garage and hadn't noticed they were really grimy.

I got a 10A bench supply. It would take too long to charge them from flat with this tiddler. So, I ensured all batteries were charged to ~3.15v and then reconnected (in series) to the Sofar ME3000SP. I just put ~4.5kWh into them and no cell ran away (in voltage terms), i.e. charging seems more balanced than before. So, cleaning the terminals seems to have made an improvement but I will need to see how they behave at a higher state of charge tomorrow. (No more charging tonight so I can go to bed and sleep with less worry!) Hopefully I can get all cells to ~3.50v by charging in series with the Sofar unit. After that I'll disassemble the pack again and charge in parallel to 3.65v with the bench supply.

@Watchout - I scanned 15 out of 16 QR codes and they are all P721s. I couldn't find a QR sticker on one of the batteries- possibly it is on the side of the battery but I forgot to check when I had the pack apart.


I am a newbie so will need to read about dendrites but I understand there are serious risks with old degraded things that have lots of energy stored in them. I plan to relocate these batteries to a waterproof box outside the garage or sell them and swallow the loss. Really I don't like this game any more. It was supposed to be a "fun" project ahead of getting solar panels installed so I could get cheap electric for working from home and crypto mining.
Capacity Tester info.

The cells a lot of people are buying are either grade B factory rejects, or removed from service. Yes the chemistry is safer than that used in US electric vehicles. But there is a reason they are cheap.
 
Yep i am also a fool that bought @ OYE. Had to know it and had to do a search beforehand.
Anyway, got 8 cells ranging from 122 to 145ah instead of the 200ah.
They have removed the QR codes on them and the stickers state P922 now.
Filed a dispute with paypal for a refund as i payed with paypal.
Lets see what develops.
Paypal states they pay for return cost.
Lets find out if they do if i have to ship them back.
 
Yep i am also a fool that bought @ OYE. Had to know it and had to do a search beforehand.
Anyway, got 8 cells ranging from 122 to 145ah instead of the 200ah.
They have removed the QR codes on them and the stickers state P922 now.
Filed a dispute with paypal for a refund as i payed with paypal.
Lets see what develops.
Paypal states they pay for return cost.
Lets find out if they do if i have to ship them back.
Sorry to hear, good luck with the refund. I think acting quickly and having capacity test evidence are key.
122Ah sounds really bad. The worst one I got was around 160Ah, which almost met my need. In the end I sold them for around 20% less (with total honesty) locally (although coincidentally it was someone who posts on these forums).
 
SCAM!!!! I bought 64 'Brand new 200AH' cells tested them and only got 117-133AH. Watever you do do not buy from this company. They only sell used and substandard cells. Don't fall for their cheap prices there is a reason for it. They insist the batteries are new and refuse to resolve the issue. They have no interest helping their customers. Please see my test results below.
 

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SCAM!!!! I bought 64 'Brand new 200AH' cells tested them and only got 117-133AH. Watever you do do not buy from this company. They only sell used and substandard cells. Don't fall for their cheap prices there is a reason for it. They insist the batteries are new and refuse to resolve the issue. They have no interest helping their customers. Please see my test results below.
 

Attachments

  • 117.jpg
    117.jpg
    143.9 KB · Views: 2
SCAM!!!! I bought 64 'Brand new 200AH' cells tested them and only got 117-133AH. Watever you do do not buy from this company. They only sell used and substandard cells. Don't fall for their cheap prices there is a reason for it. They insist the batteries are new and refuse to resolve the issue. They have no interest helping their customers. Please see my test results below.
Was this the OYE store?
 
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