I didn't get a chance to post this is the thread about the guy getting a low voltage reading on his ProVari. This is from the manual:
"LED OFF – In this mode, the pushbutton LED will not light up when you press the button during normal atomizer use. The low battery alert will not flash when this mode is turned off. (Stealth Mode)"
I knows that's true for the v2.0. I turned off the LED one time since it was on my nightstand and started flashing just when I was about to go to sleep. I forgot about it and vaped it the next day until it just stopped firing because the battery was dead. The v2.5 must be different (even though it's not supposed to be), because I have read too many posts by people saying their's blink with the LED off and 2.0 vs. 2.5 is all I can think of that would account for the difference. I haven't tried it with my v2.5.
Regarding consistency, there is a thread somewhere where I and at least one other member were discussing how we can tell that the battery is low. Personally, I get one or two weak drags and just as I'm thinking WT* was that? the light starts blinking. Not many people agreed with us as I recall.