well, I've never found references to 3,4,5,6 etc hours of vaping very helpful especially for new users. It's very subjective.
So I just counted puffs on my Smokeless Image Volt batteries. It's still subjective (you can have longer or shorter puffs) and here's what I get (with standard cartos):
320mah 78mm battery - 150-180 puffs
650mah X2 battery - 350-400 puffs
900mah x2 battery - 510-580 puffs
Now, vaping is not the same as smoking but a (very) rough estimate is 15 ecig puffs = 1 analogue cigarette. So if u smoke 10 cigaretes per day or less - 1 78mm battery may last a whole day for you (but 2 definitely will).
So I just counted puffs on my Smokeless Image Volt batteries. It's still subjective (you can have longer or shorter puffs) and here's what I get (with standard cartos):
320mah 78mm battery - 150-180 puffs
650mah X2 battery - 350-400 puffs
900mah x2 battery - 510-580 puffs
Now, vaping is not the same as smoking but a (very) rough estimate is 15 ecig puffs = 1 analogue cigarette. So if u smoke 10 cigaretes per day or less - 1 78mm battery may last a whole day for you (but 2 definitely will).