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testing the batteries/cells out of an LG Chem RESU-7H system
#31
Would you look at that, I think you're right!
The dimensions alone would give it away. The 7H is wider that it is tall...
7H is about 700mm tall (~27")
10H is about 900mm tall (~35")
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#32
Note that the entire page https://s.click.aliexpress.com/e/_dVSfDO4 is full of inconsistencies starting with jh3 isn't found on the page, the product details PRODUCT DETAILS Brand Name: Riskcell Capacity: > 40Ah~., Product Description High capacity 3C / 5C 3.7v~.
Yes 400bird the cells pictured at bottom of pade do read LGY, my bad.
Later floyd
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#33
I've got one cell that is self discharging slowly.
Less than one week it dropped from 3.1 to 2.4v
Otherwise they look pretty good.
I have cycled 2 packs, both were about 48ah on the 3rd cycle. I'm going to cycle the remaining 3 once it cools off a bit more. Then put them up for a few weeks or a month to closely monitor for self discharge.
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#34
Well 10 days later and that self discharging cell is now down to 0.5 volts. She's dead.

I may disassemble that pack or pull that cell as reassemble as a 6s. I would just need to figure out how to connect the end tabs back together. I guess it really just depends on how it comes apart.
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#35
Decided to push the first pack for a full discharge test.
Pack has been in storage for a week or two, was at about 3.7v per cell.
I charged it to 4.2v at 30 amps, then discharged at 30 amps down to 3.0 v

You can see the knee on the bottom end of the scale happens at about 3.4v. No idea where the top end knee would be, it looks dead straight once the load is applied. I haven't figured out the time scale on the graph, but it took about 2 hours for the discharge.

Total measured capacity on discharge: 56.8 amp-hours
11% loss from what we believe to be the specification of 63 ah
I think I have cycled this pack 3 times from 4.1-3.4

What do you think? Seems acceptable to me. 
I may cycle the 4 other good packs, but will probably stick to 4.1-3.5 volts.

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#36
Wow! Not bad. That is acceptable, if your other 4 packs test as good that means about 7 kWh.

I still haven't done a full discharge.need to charge all the battery pack from the battery I will be using for the regenerative discharge least the lowest two. Need more capacity to discharge into.

I had a collapsed lung last year so am being extra careful about the smoke. Today was the first day in about a week that I haven't smelled smoke.

Later floyd
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#37
I finally was able to test one module unfortunately I had the x8 set to discharge to 3.5v not 3.0v . The module started at 29.359v and discharged to 24.5v. (3.5v cell) I will confirm this after The weather cools down later tonight.
Results 52.839Ah 118 minutes
5mv low cell 3.518v high cell 3.523v.

later floyd
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#38
Awesome! That's probably close to what I had at 3.5v/cell

I wish we could find a spec sheet on these cells. I can see the voltage fall off on the low end, I wonder what the upper limit would be? I assumed it was 4.2 volts, but the voltage curve doesn't spike like I expected.

This heat is rough, awful time to test cells. Once it cools down, I will probably cycle each pack 2-3 times with just a single full cycle.
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#39
Hi Bird/Floyd
I have been given 3 of the Resu-10h units and I’ve only pulled the first one apart so far but it’s not looking terribly optimistic for them. All cells are between 0-1v
What would model charger would you recommend I get to nurse the v up before I can use the x8?
Electrician by trade but I’d like to learn how to save these if possible. Many thanks
Jack
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#40
Wow, where are these things coming from?

Congrats on your find!

I used an adjustable bench power supply with the current set low (0.1 amps) and monitored the cell voltages and temperatures.

The x8 has an adjustable precharge, I believe you can turn the voltage down pretty low and turn the time up to 30 minutes.

There are about 1000 warnings and more reasons not to recover cells below 1 or even 2 volts. So make sure you watch them closely during recovery. Once they are recovered you aren't out of the clear. If you are going to put them into use for something just make sure it can't burn the house down.
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