Yes, many variables.... what mAh rating on the battery, what power levels used, how long each draw, and so on.
In general, if looking at total life of a Lion, number of charge cycles is key. Typically rated around 300 full ones, that.
If time to recharge, all those variables come into play. And getting a feel for your hardware and vaping style can take a little bit.
IF using something like a 1300 Spinner and a T3S, I generally just charge when it's time to refill.
Something like a single 18650 box or tube and a Kayfun, I'll just swap in a new cell when the voltage gets down around 3.6(ish), since charging before fully depleted increases the service life.