i just wonder, how long do 2 drops of VG last for u guys ? i drip 1 - 2 drops directly on the atomizer and 1 - 2 drops on the cartridge itself (on the bottom, middle and top, so its filled with liquid). that kind of procedure for me last about ~20 - 35 good puffs, then it runs out. is that normal, or a problem ? should it last longer? cuz just, i have to go out with my glycerin bottle with me, if i want to smoke outside for a few hours.