I've had my bolt since 2/17 and a couple days ago it started not hitting like it did. I tested it and found with a new fully charged18650 batt at 4.1v, with a regular, 1.7ohm carto, ce2, and everything I tried, it only reads at 2.8/3.0v, the main thing now is that i can't even get a reading because there isn't enough power with the carto to give a reading. I'm using my LED volt reader. With out the carto it reads normal 4.0v and as soon as I put a carto on it won't read, the led flickers, and gives hardly any vapor, and I'm talking tiny! I tried the exact set up on my friends bolt and his was way better, lots of vapor! Something isn't right! I also had the 510 connector come totally loose. I sent them an email, now waiting for a reply! Bummed out!