It may not have anything to do with the battery calibration, but your phone never actually goes dead, if I correctly understand how these things work (feel free to chime in, anyone).
It's really bad for the battery for it to actually die, so your phone tells you before it actually happens and turns itself off before it goes dead dead. If the calibration is off, it will tell you prematurely, and it shuts off earlier than it should. That's if.
The method of calibrating, I learned from Pastafarian, cos he said that's what worked for the Moment. We're only assuming it works the same for the Intercept, but I think it's a correct assumption.