New trouble shooting item. I noticed yesterday when the vapor deteriorated that I usually add more juice. My first action now is to take the cartridge off and smoke the atomizer till there's only a minute amount of vapor. Put the cartridge back on. If you find that there is minute smoke, add a drop or two of liquid-no more than that. I am finding that most of the problem here is that there is too much juice in the atomizer, not too little. This was 100% of the time!
Next, I take long soft smokes and space them a big longer apart.
My 901 actually lasted more than a half a day without doing anything except smoking the atomizer alone when my vapor diminished!!! I added a drop or two of liquid only twice, and I went thru less than 2 batteries. Problem free in my book.
You'll find it's amazing how many times the atomizer is flooded compared to needing more juice.
Also vape with the cig pointing more down than up.