I had bought some Eagletac 18650 with the blue shrink wrap (4 of them) back in 2010 and now only 1 will charge properly to 4.2V while another one maxes out at 4.18V. The other 2 bad ones will just go blank in my Nitecore D4 after about 10 seconds.
I should have gotten a charger with resistance test. Bought the Folomov A4 and now regret that I should have bought the Xstar Dragon VP4 Plus, instead. Oh well.