Only long term is going to be the true test, but so far they seem to be doing well. I put them in a flashlight on receipt and turned it on to let them die down so I could give them a fresh charge. It took overnight, but I don’t know how long, because they went out sometime during the night. I charged them when I got up this morning. I don’t have a charger that gives me any readouts, so I can’t verify the specs. However, I tried this in my e-cig and it has worked all day for me. The end has not gotten hot like it does with some batteries. So.. great product if I can replace my expensive batteries with these.