Because the charge rate is so slow around 3.8 is roughly half give or take on the cell. In that hour it only saw 375mah and not all of that made it into the cell. So nothing wrong with the cell it’s just a slow charger. I have the folomov chargers the a2,a4, opus 3100, xstar vc2 among others. Ditch the nitecore get something that can do at least 1 amp across 4 slots. Nitecore makes good lights, their chargers are hit and miss. Usually when hjk test them there are issues they have to fix. At least in the sc2 and another I forgot the name of. Imr batteries you can have the a2 for 15 dollars I think. And the a4 25. My a2 stays at work for if my vape dies I can blast the cells at 2 amps for half a hour and be fine the rest of the day