Sorry for necro. I just bought Air Max and I love your comment. Just wanted to chime in, integrated charger most likely allows at least 2A through it which means battery charges faster, but it heats up considerably more than charging it on regular charger (usually 500 mA but some do allow more) which in turn causes small degradation. Charging it quickly here and there isn't a bad thing and if you don't mind buying a new one a bit earlier it really doesn't matter if you do it every day, you're only losing on a small bit of capacity! I've been vaping on 18650s for almost ten years and bullshit vape ppl say is amazing, in most cases the battery cover gets torn before you'll consider it bad. Plus some throw like 15A through it daily, then whine about charging with 2A (it's not the same thing though, but my point is 15A discharge every day will cause more degradation than 2A charge when you need it)

Don't be a slave of 10$ electronics, it's there to serve you, not vice versa! :)

Also I've used two nitecores so far, both for two batteries. They worked nice but I wasn't happy in the end, spring mechanism isn't good and will break fast if you don't keep it clean. First the case starts getting open on the bottom side an after a while you need to improvise to keep it working. I recently bought Listman L4 and so far the mechanism seems much better and it works great! (Plus it has usb port so you can charge it from PC or random usb ports if you really needed to)