Well what I can say about our batteries is that you can use and charge as and when you like don't need to wait till it's fully empty or what just make sure you unplug it when your indicator says it's fully charged.
As for mobile phones and laptop. Occasionally you have to let it discharged till 0% like maybe every half a year or so. Due to the fact that those electronic devices come with things that will calculate battery time left. And occasionally the so called "calculation" will go somewhat off that's why after you let it go down to 0% and up to 100% again the "calculator" will recalibrate itself.
thats true for the calculator thing. but its like once in a long time only hehe. for me, i use till my pv starts indicating low batt then i will swap the batt.
but for most pv, once u r familiar with it, u will roughly know when the batt goes low. esp when the flavor, th n vapor dun come out as per norm according to ur pv. thats when u roughly know its low and time to charge