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Green Sony cells just suck
#51
Those clusters of 4 reds are strange

When 1 cell goes red so do the other three in the tester

Any idea why?
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#52
(02-07-2019, 05:35 AM)Chablis_m Wrote: Those clusters of 4 reds are strange

When 1 cell goes red so do the other three in the tester

Any idea why?
Not really sure. Could be temp related but house temps don't really change much. The cat could be sleeping on them or the dog panting waiting for the results. Tongue
No just kidding but no I'm not sure but here are the latest results in this ongoing investigation.
It may be that the cells are slowly recovering due to the charge and discharge cycles. Like it's being exercised.
I also have changed from immediately retesting the same cells in the same charger to letting them rest a day or so between testing. Always putting them back in the same charger of course. Got to keep things scientific.
That could be it. They may be finding their equilibrium and finally settling down to their normal levels.
I should have all of them at Test 8 this weekend and will continue for at least 10 tests if not 15 tests. Don't want to go too much more as they are all within my 2200mAh range and I want to use them not abuse them. Big Grin

Wolf
If 18 X 650 = 2200+mAh then we have power! 
May all your Cells have an IR of 75mΩ or less Smile
Last count as of 8/7/2019
Total Number of Cells Recorded and processed                 6149
Total Cells required for PowIRwall                                   2856
Total Cells ≥2200mAh, ≥80%, ≥35mΩ, ≤75mΩ, ≥4.12V   2760
For Info Google Drive
Not your average Wolf       
            Cool
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#53
Latest data in the "Green Sony Cell Debate"

I don't know  but they look relatively consistent too me. Variances of ~200mAhs but not per say a steady decline.
So I am giving the cells a rest for a couple of days. I need the 12 slots for a couple of days to catch up on my cells waiting to be tested.
Took a V and IR reading after the 8th test just to check.
Did a Min/Max on the results so far so you be the judge. I will go to test 11 unless you guys want to go a full 15. 
I still have 37 cells I havent tested yet so I want to get started on those.

Here's the sheet.


Wolf

PS: Built a Cell Testing launch platform this weekend. 0V to 1V on the left 1V to 3.3V in the middle and 3.4V to 4.2 on the right.

LEDSchlucker, DCkiwi, camthecam like this post
If 18 X 650 = 2200+mAh then we have power! 
May all your Cells have an IR of 75mΩ or less Smile
Last count as of 8/7/2019
Total Number of Cells Recorded and processed                 6149
Total Cells required for PowIRwall                                   2856
Total Cells ≥2200mAh, ≥80%, ≥35mΩ, ≤75mΩ, ≥4.12V   2760
For Info Google Drive
Not your average Wolf       
            Cool
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#54
UPDATE:
Here is the latest result from the cycling test of the "GREEN" Sony cells.
Conditional formatting is for highest mAh is green and lowest is red. Just because its red does not mean it is "bad" just the lowest mAh.
I would have no problem using them in my powerwall.  Smile
Tell me what you think. I just don't see a loss of 100mAh per cycle consistently.
Should I do more cycles or is 11 enough?
Got another 34 cells to go we will see.



Wolf
If 18 X 650 = 2200+mAh then we have power! 
May all your Cells have an IR of 75mΩ or less Smile
Last count as of 8/7/2019
Total Number of Cells Recorded and processed                 6149
Total Cells required for PowIRwall                                   2856
Total Cells ≥2200mAh, ≥80%, ≥35mΩ, ≤75mΩ, ≥4.12V   2760
For Info Google Drive
Not your average Wolf       
            Cool
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#55
Ok so here are the results of 24 Sony US18650GR G8 (except for 10) all of these cells where below 2.5V and each tested 11 times.
For you math wizards thats 264 individual tests.
I have 32 more cells each in different stages of the test. As soon as they are done I will post the results.
Procedure,
Initially I tested the same 4 cells in rapid succession on the same tester giving the cell no time to rest.
I did notice that temperature was not decreasing and the cells where no longer being tested within the manufacturer ~23°C recommendation.("room temperature")
I changed that and allowed the cell to rest one day after charging and then continued the test cycling between sets of cells but always to the same charger and the same slot. The temp issue seems to show up as the sharp dip in the chart.
Initial mAh test shows a good value and subsequent tests seem to indicate some trending signs to a lowering of capacity on some cells but not all.
At least not the ~100mAh or so per cycle as discussed in this thread.
Also I have changed to charging all the cells initially with a CC/CV system at 4.2V and 50mA per cell.
After their initial test they are charged with any charger that is available at 500mA per cell.
Please keep in mind that this is a rescue a low V cell experiment and not on Cells that were pulled out of a pack with 3.8V+ in them.
So without further adieu here are the test results so far.
Your comments are welcome and asked for. Please let me know as to anything you would like to see changed or kept the same for the remaining 32 Cells

 


Wolf
BlueSwordM, Generic, DCkiwi like this post
If 18 X 650 = 2200+mAh then we have power! 
May all your Cells have an IR of 75mΩ or less Smile
Last count as of 8/7/2019
Total Number of Cells Recorded and processed                 6149
Total Cells required for PowIRwall                                   2856
Total Cells ≥2200mAh, ≥80%, ≥35mΩ, ≤75mΩ, ≥4.12V   2760
For Info Google Drive
Not your average Wolf       
            Cool
Reply
#56
Update:
Here are the results so far got a few more to go and then we will have the complete results and I can go back to my life! Big Grin
Oh wait this is my life what am I saying.
Questions or comments? Would you use them in your powerwall?
As far as rescued cell with less than 3V and some at below 2 I don't think they are that bad.
I have attached the Excel sheet just in case its too difficult to see the picture as I had to cut and paste to get it all in one.
Wolf


Edit:
Ah picture sucks here are the 2 that were combined.



Much better


Attached Files
.xlsx   Sony Green.xlsx (Size: 26.15 KB / Downloads: 37)
If 18 X 650 = 2200+mAh then we have power! 
May all your Cells have an IR of 75mΩ or less Smile
Last count as of 8/7/2019
Total Number of Cells Recorded and processed                 6149
Total Cells required for PowIRwall                                   2856
Total Cells ≥2200mAh, ≥80%, ≥35mΩ, ≤75mΩ, ≥4.12V   2760
For Info Google Drive
Not your average Wolf       
            Cool
Reply
#57
OK final update the Sony green cell suck analysis has been completed.

These cells where tested from a low V of .918 to a high V of 3.73.
Charging was done using various methods as listed in the chart.
Cell # 44 to 46 were beaten up with the SKYRC tester with various charging parameters mostly mA charging cut off and mA discharging cutoffs.
I overcooked them on test 9 and exceeded the cells recommended cutoff mA charge and discharge specs and it shows in the following tests.
The SKYRC was set to cut off everything if temperature went above 45° C but it never did. Got close but not close enough. 

My conclusion is that they are not bad cells.
One thing of note is that the US18650GR G8 has a high IR from the get go and is no indication of a bad cell. 
One oddity I did find is that after a nice slow wakeup charge the IR dropped pretty dramatically an anomaly I have not found in other manufactures cells.
If I go with the  standard IR readings of most other cells (My own conclusions coming in a report soon) I would bin them for sure. On the other hand I don't think I will or would use them in a powerwall with other cells. I just think the IR difference is too much to pair them with sub 75 mΩ cells.
As a group of just sony cells I would have absolutely no problem with them. If I had 3000 of them I would build them into a powerwall without a worry.
As 20 or 30 cells in a diversified cell combination of 200 I am not so sure I would do that.
One more note the cells do like a small rest between charges it seems that if I let the cells rest for 8 to 12 hrs and then discharge them their consistency seems to be better.
The Min Max of these cells through 11 cycles was at the highest 12.8% and at the lowest 1.18% (other than the cell I beat up Big Grin )
so not so bad and they certainly did not loose 100mAh after each test.
So here is the chart and as always like it, leave it, or lump it. Tongue comments always welcome and required.
If you want the sheet uploaded in xlsx let me know.
Wolf
Oz18650 and DCkiwi like this post
If 18 X 650 = 2200+mAh then we have power! 
May all your Cells have an IR of 75mΩ or less Smile
Last count as of 8/7/2019
Total Number of Cells Recorded and processed                 6149
Total Cells required for PowIRwall                                   2856
Total Cells ≥2200mAh, ≥80%, ≥35mΩ, ≤75mΩ, ≥4.12V   2760
For Info Google Drive
Not your average Wolf       
            Cool
Reply
#58
Thanks for all the effort in testing and sharing.
While i have not used the info much yet, I am sure it will be very interesting and useful once my testing and data collection gets under way.
I am sure your findings week be useful to many other people too.
My initial plan was to dispose of all low voltage cells. This had been revised as a result of discussions about how low voltage cells can be recovered.
I am sure many other people week have gained a lot from this testing, data collection and sharing too
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#59
Tested also some sony, no problem found.
Only the ir puzzles me, it is not consistent. Huh
The ir test was every time on the same voltige, exact at 3.45
Even some cells improved in soh and capacity, but that is not strange.
Ir on some cells was going down and on some cells was going up? Huh

Those were my tests, nothing or no one can beat The Wolf! Cool

Thanks for the head up, a warend person counts for two!

sorry, the v3, v6 and the nc1 10 of each, 5 tests on each
Selling everything at marketplace.
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#60
nice demo.
if there are any particular cells with a high percentage of duds it would be older red sanyo's not sonys.
this is my experience.
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