Old LiIon Battery voltage settling/drop after full charge

[Dave_H]

@Dave_H would be interesting to see how the ones with high discarge rates behave when you discharge them with a high (enough) current and recharge.
Not full discarcharge, just a few pulses.
I am curious about what happens and I have no such cell yet.

Some of the better ones are Samsung ICR18650-28A which if genuine should have started out as good quality cells, however they are now "used" with unknown history.

One of the less-good ones has dropped to around 1v in roughly a week, so not promising.

One of the better of the lot has inched down to just below 4.0v in the same interval. I can run a check on this one., initially running overnight in a small 1x18650 light set on low setting (typically 0.12A).

Dave

 

[aznsx]

One of the less-good ones has dropped to around 1v in roughly a week, so not promising.

I would retire that one immediately without second thought. I don't have much money, but cells aren't expensive enough to justify risks (IMO).

 

[Dave_H]

I would retire that one immediately without second thought. I don't have much money, but cells aren't expensive enough to justify risks (IMO).

Good advice, this cell dropped below 1v and was headed for discharge/disposal. Even another which had dropped not nearly as much (down to 3.86v) did not hold up well even in light load testing (only 7 hours at 120mA down to below 3v) for a 2800mA cell. They are getting weeded out.

Dave