Heliguy, watch the amps. Using LR (especially dual coils = amps hogs) may result in higher amps consumption which will drain battery faster. Raising the watts may, or may not (depending on the atty ohms and watts setting), raise the amps used. Battery life will be subjective relative to variables including how long and how often you press the button and amps consumed (amps consumed is still the deciding factor but that will be a combination of both length and how often you press and the amps being drawn by the Ωs/watts setting). So, what you are getting compared to others is difficult to compare.
The very least hours of useable batt life I have experienced so far is about 15 hours (heaviest vaping days) but I have seen 18 hours on other days (again, subject to the variables mentioned above). Once you see your average batt life, based on YOUR usage, if you are concerned about getting thru a night - just plug in at some point during your day to top off the batt. You can vape while charging so plug in either at work, in the car or at some point during your day for a couple hours and that should get you thru. Or, of course, you can do what I (and others) do - get another DARWIN!!
When I run 2 with different juices or attys/cartos, by bedtime neither is below half batt on the gauge (usually both showing 3/4 or better). But, plugging in for an interval or two (depending on how long plugged in) should certainly get you thru the night on a single device.
Some are posting about 2+ days but that certainly is subjective to all of the above. Any battery life will be a function of the drain placed upon it. After trying over 30 devices and most of the batteries (AW IMR being the largest capacity I have used other than Darwin), Darwin far outlasts them all.
Hope something in this is helpful.
