Off topic, but Mooch has a video about how to get the most life from your batteries. He mentions something about trying to run them between 20-80%. I have no way to check that (my charger just has LEDs and my multi-meter is cheap analog... I do need a good digital meter for working on cars and it would be nice to use on vape batteries as well) And then there is something about storing batteries... keep them less than fully charged (3.7 volts?) I think this was the video: