That is true. The vape slowly diminishes with a mech. Once you feel like its getting too weak, you just put in a fresh battery and put the other one on the charger. I really start to notice around 3.6 V, so that's when I do the swap. It's usually after several hours of vaping on the SLR coils, which definitely suck a lot of power. The good part is that shallow discharges are less stressful on the battery than deep discharges.That's one concern I have with mech.mods. I'm not sure I'll like that getting a good vape that diminishes as the battery dies. Also I see these batteries say not to drain below 2.5v. With a mech mod how do you know when that occurs. I guess I'll test them in the provari and get a feel for it over time.