Konion / Sony US18650 cells

[67spyder]

I am collecting cells from dead drill and laptop batteries and have mostly molicel IMR18650E but also have a few (80-90) of these green sony US18650 (GR and V). From what I have read they have a different chemistry than my other cells and should not be mixed due to a slightly different finish charge voltage. Any thoughts or ideas??

 

[67spyder]

Forgot to mention, I have 6 light purple cells LR1865BE all six get warm when charging at about 3.5V. I pulled them from the charger. Are these just bad cells or are they a different chemistry that has a lower finish voltage? I found a spec sheet from a retailer that made them sound like standard Li Ion cells which would mean these are junk.

 

[Ypedal]

Any used pack you open up with cells below 3.0v you can pretty much throw in the recycle bin.. if you get a pack with 4 out of 5 cells showing 3.0+ volts they are likely ok and will perform as expected..

try not to mix cell types/brands in a pack, C rate and discharge curve vary even with same chemistry.. most 18650 cells in power tool packs are 3.0 ~ 4.2v

 

[67spyder]

That sounds like good advise, which means molicell. I have about 300 of them (after tossing the ones that fail the initial voltage test) and am hoping to to have enough for 2 packs of 24s5p.

 

[neptronix]

Sorry to threadjack, but just curious... where/how does one acquire all these discarded cells?

 

[67spyder]

Through business contacts I know a battery retailer and several tool distributors. The battery retailer gives me his Li Ion batteries in exchange for all the other batteries I give him. He makes money from the recycling of them and the Li Ions that are the least financially equitable to recycle become more profitable to recycle because I separate out the cells from the rest, take the plastic to the plastic recycler and he only pays to ship bare cells to the battery recycler. The tool distributors are just happy that I come and take them away, one of them actually was just throwing them in the trash before I started picking them up.

 

[67spyder]

Forgot to mention, I own a computer repair shop so that is where I get the dead laptop batteries.

 

[John in CR]

67spyder,
A helpful hint for you is to never remove the factory tabs from good cells. It makes them easier to join them later to form packs with less heat damage risk to the cells. For toolpacks that don't have BMS's like Makita and Bosch, only remove the dead cells from the existing structure. That way you retain the matched cell grouping as well as the physical structure.

 

[Doctorbass]

+1 for John in CR and Ypedal.

Doc

 

[Ypedal]

I go one step further in the recycling of parts, when i cut the extra tab material going to the toolpack pcb ( using a dremel with cutting disks, just score the tab then fold it over and it breaks easily ) i use that tab material to link pack segments, it solders easily ! :wink: