18650 Harvesting Flow Charts

Wolf

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As a community we all have our different ways of processing cells and I wanted to take the opportunity by starting this thread to find some common ground on how we all should harvest cells.
This is not meant to be a "be all end all" but more of a guide for new members and maybe some senior members alike.
Constructive critique is appreciated as any input that furthers our voyage will make us all better harvesters.
In this instance I will share my Flow Chart thatI use it to process my 18650 cells. Kudos to Daromer who as far asI know it was the first one to publish his flow chart.
Otherchemistries and formats are going to be different so hence the title "18650 Harvesting Flow Charts"

My chart assumes that you have a supply of 18650 battery packs and have a good understanding of what to expectthe pack has for cells and what the likely mAh is of the cellsthat you will be harvesting.
For Examplea 2.5Ah 14.4V pack will most likely have a 4s1p setup with 2500mAh cells
the same runs true for a 6Ah 11.1V pack will most likely be a 3s3p with 2000mAh cells
You should by now be able totell if the packs are 3s2p or 4s4p and so on.
This chart also relies heavily on IR (the internal resistance of the cell as measured with a 1kHz AC 4 wire meter) as the initial pivot point.
Meters such as the YR1030, YR1035+, and RC6563 supply us with that measurement,are reliable and with my testing have been accurate.

If I open a pack and I spot cells that are corroded or have physical damage I close it up and wrap ducttape around it as it is much easier to drop off at the recycler than individual cells.
The chartassumes if you open a pack you will separate the plastic casing, electronics, and nickle strip residue for recycling.
BTW please publish your flow charts so we can compare notes.
Here is my Flow chart:

image_bxfygz.jpg


Wolf
 

Wolf

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Redpacket said:
Would be great tocollaborate& get these into the FAQ with Korishan

Yes that is why I started this tread.
FAQ maybe when its refined and if we all can agree, :p

Side note:
I'm still on the hunt for a FET that will open proper at a bit lower V for the ESP32 to get full flow.
Of course I can always rewrite the sketch for a Nano its just the speed of the ESP32 that's the advantage right now.
Wolf
 

OffGridInTheCity

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Suggestion - maybe2.6, 2.7, or 2.8v instead of 3v to begin charging as2.8v is often the specified low v for 18650 rather than 3.0v. Maybe 'newer' cells are bit less risk than 'older' cells also. For a real worldexample, the RING battery packs (newer cells - e.g. not likely to be stressed much)have a significant % where the cells are at 2.6v and they're perfectly find just charging them directly (using the OPUSs).

OK, just a comment... :)
 

Wolf

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OffGridInTheCity said:
Suggestion - maybe2.6, 2.7, or 2.8v instead of 3v to begin charging as2.8v is often the specified low v for 18650 rather than 3.0v. Maybe 'newer' cells are bit less risk than 'older' cells also. For a real worldexample, the RING battery packs (newer cells - e.g. not likely to be stressed much)have a significant % where the cells are at 2.6v and they're perfectly find just charging them directly (using the OPUSs).

OK, just a comment... :)
Perfect good point.
I feel that if a cell is at ? 2.5V and it is a rather young cell with good IR you should have no problem popping it into a charger/tester at 1A.
If a cell is < 2.5V I feel it would be wise to recover charge to 3.0V. The difference in charging time between 2.8V to 3.0V is maybe a half hour or so.
But hey that's why we are discussing it. :)
Wolf
 

507PowerWall

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Wolf said:
OffGridInTheCity said:
Suggestion - maybe2.6, 2.7, or 2.8v instead of 3v to begin charging as2.8v is often the specified low v for 18650 rather than 3.0v. Maybe 'newer' cells are bit less risk than 'older' cells also. For a real worldexample, the RING battery packs (newer cells - e.g. not likely to be stressed much)have a significant % where the cells are at 2.6v and they're perfectly find just charging them directly (using the OPUSs).

OK, just a comment... :)
Perfect good point.
I feel that if a cell is at ? 2.5V and it is a rather young cell with good IR you should have no problem popping it into a charger/tester at 1A.
If a cell is < 2.5V I feel it would be wise to recover charge to 3.0V. The difference in charging time between 2.8V to 3.0V is maybe a half hour or so.
But hey that's why we are discussing it. :)
Wolf
 

Korishan

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507PowerWall: Not sure what your last post was about. Please if you answer a quoted post that your reply is "outside" of the quoted section. If you want to make sure of the quoted section, always preview before posting.
 

507PowerWall

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Korishan said:
507PowerWall: Not sure what your last post was about. Please if you answer a quoted post that your reply is "outside" of the quoted section. If you want to make sure of the quoted section, always preview before posting.

I did qoute, but sometimes this happen.... moreover, Im not able to see my own post that you are making reference :(

CG.
 

Korishan

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507PowerWall

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SeRiusRod

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It seems that only RedPacket is taking heating into account in its processing. How do you do it. With the bare hand approach?

I've found myself how difficult is to physically control cell heating and at the same time cooling the testers without affecting each other.

I'm designing an ESP driven gadget to give those additional features to the existing chargers & testers. Each ESP will have 8 temperature probes that will be mounted into a 3d printed clip that I will dock to each cell. I'll send measurements to a DB and grafana for reading and alerts.
I'm figuring out how to measure voltage so I can log the temp along it. Measuring voltage would be easy, just adding multiplexers and perhaps an ADC for differential reading, but..
Is it possible/reliable to read voltage while being charging or testing with an independent device?
Would be "good" to join the negatives on Opus/LII500/TP4056 cells for simplifying voltage reading circuit?

That counts as a part of my processing flow? ;9
 

Wolf

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SeRiusRod,

Ah the heating of the cell.... or "Heaters" as we know them.

There is one thing I have observed and that is, if the IR is measured first and it falls within my cheat sheet perimeter the chances of having a hot cell is virtually eliminated.
I have tested the so called Sony heaters with above my cheat sheet IR and they have run hot some very hot. The same cells with proper IR did not heat up beyond the normal charging / discharging temp.

So that is why I do not have a temp check in my flow chart.

Wolf
 
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Redpacket

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I've updated the flow chart to larger size & included IR testing.
Let me know any thoughts....
Cell testing flow chart bigger w IR.jpg
 

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OffGridInTheCity

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Excellent flow chart. I might do this section in terms of '% of original specs' instead of a fixed 2000mah. Perhaps 80%? As its OK to build a DIY powerwall battery with 1700mah cells that are 80% of 2150mah original specs.
1612278835298.png
 

Overmind

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Note that some power tool high drain low capacity cells can reach below 1V and still be good (near max cap). I recovered some like that (like Samsung 13 and 15Qs).
 
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