As to why I am charging them (presently) to only 3.7V, I am using an old DC power supply current limited at 0.27A. A pretty slow process which requires a bit of monitoring. Which brings up the next point, I certainly do need some sort of proper single (or multi cell) 18650 charger, and one that analyzes could not hurt.
I will give them a go charging up to 4.2V or so and let them sit. Just will take a bit of time. Was wondering if the time was worth it, but I guess the only way to really know is to run a more quantitative test than I have. That’s were the analyzing charger would be the most helpful, but I may use some of the things I have on hand.
Long term I will pick up a charger, but was also thinking that the charger would be a lantern like this: *BLF LT1 Lantern Project) (updated Nov,17,2020) . I figured I would need some 18650 cells for it, and when I came across the laptop pack figured it would work for starters. The light will not demand high current best I can tell from the thread.