As promised, here is my thread where I will post the results of my harvesting. Every so and so often the question comes up what is to be expected when reclaiming cells from old laptop batteries. The answer is always the same, it depends and if you are unlucky you will get hardly anything useful. This thread is aimed especially at people new to the business but veterans are also invited to have a look of course 
Disclaimer: The results here should be taken as one of several possible outcomes when harvesting cells. I'm not trying to prove anything, I'm just providing an example and breaking smaller lots of batteries I get down to individual cells in terms of statistics.
At the moment I get most of them on eBay when I find a cheap offer. A cheap offer at the moment is 2 EUR or less per battery here in Germany, excluding shipping.
This is also quite interesting for me, not because I'm too bothered about success rates, but because I like some good statistics. So I will gladly write this stuff down and maybe someone will find this useful to get a clue of what can be expected when doing this sort of thing. I will also calculate the costs to see what I've effectively paid for these used cells.
I will update this first post as soon as I have new data. If you want to do this as well, feel free to grab a post where you do this. I will put links in the first post so your data can still be found in case this thread gets a bit longer. I will not put up any rules if you want to do this, choose any format you find suitable or just do it like I'm doing.
Here we go:
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Batch 1, eBay:
34 batteries, 31 good, 1 noname,2 corroded
Most of these batteries were HP ones and that doesn't matter as such, but one specificthing about them was interesting:
There was a pattern emerging when I checked the voltage of the cells after I freed them from their case. These were 3S batteries, as it is very common, and the first cell had good voltage like 3V and more, the second cell was always lower than the first one and the third one was always lower than the second one. And we are talking about big differences here like 1V between each cell.I guess this is a case of failing BMS's, the battery died well before its time because the shitty BMS couldn't keep it balanced and then just killed it. First tests support this, many of these cells are very good.
But, remember the disclaimer, this doesn't mean anything, we are talking about a very small sample size here and this is not necessary the case all the time with HP batteries.
65 dead cells (0V / strange behaviour / corrosion)
123 usable cells, all of them branded cells, the noname battery had bad cells
188 cells total, 34,6% failure rate before testing,0.65 EUR per testable cell
4 cells didn't make it to testing, voltage dropped below 4V after charging
8 cells with very low capacity
111 tested sucessfully, 0.72 EUR per usable cell
Capacities:
14xx: 5
15xx: 3
16xx: 4
17xx: 15
18xx: 14
19xx: 11
20xx: 24
21xx: 16
22xx: 8
23xx: 6
24xx: 3
25xx: 2
Total: 219.979mAh
Average: 1.981,79mAh
Price per Ah: 0,364 EUR
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Batch 2, eBay:
23 batteries, 17 good, 2 noname (surprisingly with branded cells), 1 noname and old (PowerBook G3, around year 2000, Panasonic 17670s), 1 old (again, PowerBook G3, but original, Panasonic 17670s),1 very old (Compaq1400mAh, proprietary cell format) and 1 LiPo
Started taking them apart, few surprises:
The old Compaq battery: Proprietary Panasonic cells, still working! No use for them though, so they will go to the recycling center.
3rd party and original PowerBook battery: Both have the same Panasonics, 17670 format
Among the 17 good, branded ones there was another old battery from Toshiba with working Sony 17670 cells.
Both newer noname batteries had branded cells in them as well, one of them was a 12-cell with Samsung ICR18650-26FU. -26F is very common, -26FU is a bit weird and you find only very little about them.
Interesting: Many of the 17670s from the 3rd party PowerBook battery died over night while most of the same batteries from the original battery are working fine. Obviously this might be a coincidence, but it is interesting nevertheless.
8 dead 18650s (0V / strange behaviour / corrosion)
12 dead 17670s (0V / strange behaviour / corrosion)
63 testable 18650s
21 testable 17670s
18650 failure rate: 12.9% before testing (8 of 70)
Not counting the 17670s for the costs, full costs distributed across the 18650s only
0.49 EUR per testable 18650 without Sanyos
0.29 EUR per testable cell with Sanyos, will test them separately to see which can be used
4 cells with very low capacity
6 hot Panasonics, very low capacity as well
53 usable cells for now, 0.58 EUR per usable cell
20 red Sanyos, cold while charging
16 tested ok, 4 had very low capacity
No heat during discharge, will check for heat during recharge
24 red Sanyos, hot while charging
Put them through a cycle, some stopped getting hot, some got warm (so less heat than before), some got hot as before
Will continue to cycle them
Capacities for the 53 tested 18650s:
14xx: 2
15xx: 9
16xx: 8
17xx: 4
18xx: 1
19xx: 1
20xx: 9
21xx: 3
22xx: 10
23xx: 3
24xx: 3
Total: 102.957mAh
Average: 1.942,58mAh
Price per Ah: 0,299 EUR
Capacities for the 20 Sanyos that made it through testing:
14xx: 1
15xx: 2
16xx: 1
17xx: 0
18xx: 3
19xx: 7
20xx: 4
21xx: 2
Total: 38.063mAh + 102.957mAh = 141.020mAh
Average: 1.931,78mAh
Price per Ah: 0,218 EUR
Capacities for the 21 17670s that made it through testing: Most of them were rated around 1200mAh and had between 900 and 1200mAh left
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Batch 3+4, eBay, came together from same seller:
45 batteries, 40 good, 4 noname, 1 LiPo
Some Lenovo batteries had a mix of four 18650s and four cells in a proprietary format, looks weird...
The Nonames had Sanyo cells, apart from one and that one had bad cells, so no working noname cells from that batch either.
50 dead cells (0V / strange behaviour / corrosion)
146 usable cells, all of them branded cells
106 red Sanyos, who knows...
22 non Sanyo heaters, also who knows...
315 cells total, 15,9% failure rate before testing,0.74 EUR per testable cell without Sanyos and the other heaters, 0.38 EUR per testable cell with Sanyos
58 cells didn't make it to testing or have very low capacity
88 tested between 1500 and 2600mAh
Needless to say that this is a pretty horrible result. Many bad cells, many Sanyos and usable cells at over 1 EUR per cell.
----------------------------------------
Disclaimer: The results here should be taken as one of several possible outcomes when harvesting cells. I'm not trying to prove anything, I'm just providing an example and breaking smaller lots of batteries I get down to individual cells in terms of statistics.
At the moment I get most of them on eBay when I find a cheap offer. A cheap offer at the moment is 2 EUR or less per battery here in Germany, excluding shipping.
This is also quite interesting for me, not because I'm too bothered about success rates, but because I like some good statistics. So I will gladly write this stuff down and maybe someone will find this useful to get a clue of what can be expected when doing this sort of thing. I will also calculate the costs to see what I've effectively paid for these used cells.
I will update this first post as soon as I have new data. If you want to do this as well, feel free to grab a post where you do this. I will put links in the first post so your data can still be found in case this thread gets a bit longer. I will not put up any rules if you want to do this, choose any format you find suitable or just do it like I'm doing.
Here we go:
----------------------------------------
Batch 1, eBay:
34 batteries, 31 good, 1 noname,2 corroded
Most of these batteries were HP ones and that doesn't matter as such, but one specificthing about them was interesting:
There was a pattern emerging when I checked the voltage of the cells after I freed them from their case. These were 3S batteries, as it is very common, and the first cell had good voltage like 3V and more, the second cell was always lower than the first one and the third one was always lower than the second one. And we are talking about big differences here like 1V between each cell.I guess this is a case of failing BMS's, the battery died well before its time because the shitty BMS couldn't keep it balanced and then just killed it. First tests support this, many of these cells are very good.
But, remember the disclaimer, this doesn't mean anything, we are talking about a very small sample size here and this is not necessary the case all the time with HP batteries.
65 dead cells (0V / strange behaviour / corrosion)
123 usable cells, all of them branded cells, the noname battery had bad cells
188 cells total, 34,6% failure rate before testing,0.65 EUR per testable cell
4 cells didn't make it to testing, voltage dropped below 4V after charging
8 cells with very low capacity
111 tested sucessfully, 0.72 EUR per usable cell
Capacities:
14xx: 5
15xx: 3
16xx: 4
17xx: 15
18xx: 14
19xx: 11
20xx: 24
21xx: 16
22xx: 8
23xx: 6
24xx: 3
25xx: 2
Total: 219.979mAh
Average: 1.981,79mAh
Price per Ah: 0,364 EUR
----------------------------------------
----------------------------------------
Batch 2, eBay:
23 batteries, 17 good, 2 noname (surprisingly with branded cells), 1 noname and old (PowerBook G3, around year 2000, Panasonic 17670s), 1 old (again, PowerBook G3, but original, Panasonic 17670s),1 very old (Compaq1400mAh, proprietary cell format) and 1 LiPo
Started taking them apart, few surprises:
The old Compaq battery: Proprietary Panasonic cells, still working! No use for them though, so they will go to the recycling center.
3rd party and original PowerBook battery: Both have the same Panasonics, 17670 format
Among the 17 good, branded ones there was another old battery from Toshiba with working Sony 17670 cells.
Both newer noname batteries had branded cells in them as well, one of them was a 12-cell with Samsung ICR18650-26FU. -26F is very common, -26FU is a bit weird and you find only very little about them.
Interesting: Many of the 17670s from the 3rd party PowerBook battery died over night while most of the same batteries from the original battery are working fine. Obviously this might be a coincidence, but it is interesting nevertheless.
8 dead 18650s (0V / strange behaviour / corrosion)
12 dead 17670s (0V / strange behaviour / corrosion)
63 testable 18650s
21 testable 17670s
18650 failure rate: 12.9% before testing (8 of 70)
Not counting the 17670s for the costs, full costs distributed across the 18650s only
0.49 EUR per testable 18650 without Sanyos
0.29 EUR per testable cell with Sanyos, will test them separately to see which can be used
4 cells with very low capacity
6 hot Panasonics, very low capacity as well
53 usable cells for now, 0.58 EUR per usable cell
20 red Sanyos, cold while charging
16 tested ok, 4 had very low capacity
No heat during discharge, will check for heat during recharge
24 red Sanyos, hot while charging
Put them through a cycle, some stopped getting hot, some got warm (so less heat than before), some got hot as before
Will continue to cycle them
Capacities for the 53 tested 18650s:
14xx: 2
15xx: 9
16xx: 8
17xx: 4
18xx: 1
19xx: 1
20xx: 9
21xx: 3
22xx: 10
23xx: 3
24xx: 3
Total: 102.957mAh
Average: 1.942,58mAh
Price per Ah: 0,299 EUR
Capacities for the 20 Sanyos that made it through testing:
14xx: 1
15xx: 2
16xx: 1
17xx: 0
18xx: 3
19xx: 7
20xx: 4
21xx: 2
Total: 38.063mAh + 102.957mAh = 141.020mAh
Average: 1.931,78mAh
Price per Ah: 0,218 EUR
Capacities for the 21 17670s that made it through testing: Most of them were rated around 1200mAh and had between 900 and 1200mAh left
----------------------------------------
----------------------------------------
Batch 3+4, eBay, came together from same seller:
45 batteries, 40 good, 4 noname, 1 LiPo
Some Lenovo batteries had a mix of four 18650s and four cells in a proprietary format, looks weird...
The Nonames had Sanyo cells, apart from one and that one had bad cells, so no working noname cells from that batch either.
50 dead cells (0V / strange behaviour / corrosion)
146 usable cells, all of them branded cells
106 red Sanyos, who knows...
22 non Sanyo heaters, also who knows...
315 cells total, 15,9% failure rate before testing,0.74 EUR per testable cell without Sanyos and the other heaters, 0.38 EUR per testable cell with Sanyos
58 cells didn't make it to testing or have very low capacity
88 tested between 1500 and 2600mAh
Needless to say that this is a pretty horrible result. Many bad cells, many Sanyos and usable cells at over 1 EUR per cell.
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