i have a big question:
what battery would you trust more between a 4year old 18650 that have 70% of its capacity and a 11year old 18650 battery that have 90% of its capacity?
those 2 batteries come from used labtop
those 2 batteries are panasonic CGR18650 E
and the battery is to be used in low ah draw aplication 0.5C or less
11 year 90%
will be the better cell But …i’m only guessing .i’d charge them both up and then let them sit for 3 weeks and then test voltage of them… the one with the highest is the winner .
Cells at Gearbest are too cheap to jerk around …no matter how badly someone may hate gearbest … the safer battery will be the one in the mail .
What would be one then, gauss?
If you have some knowledge to share, then do so, it might help people new to lithium batteries or laptop pulls.
Oh here we go again 
Im with Boaz, at the end of the day the better cell, is the better cell.
and yes for high draw applications newer cells just seem to be going down in price.
and Gauss has excellent questions,… answers seem to be harder to come by.
Now that is an excellent answer!
Just a small addition. I’ve had some laptop puls keep voltage “stable”, say at 4.10V after charging, but they weren’t able to give out any current. I.e. when used in a flashlight, the light was low on any mode. Much lower than it was supposed to be.