These days battery don't require constant care. I used a OnePlus 3 for 3 years and the battery is still fine even though I never did anything special. Left it charging overnight, sometimes charged during the day... the only thing I avoided - mainly because I didn't need it - was dash charging (aka quick charging). You should avoid going too low (eg: less than 20%) and avoid heat (eg: leaving the phone inside a car on a hot day), but that's the rule for most batteries we use on computers, phones, etc. Asus includes a setting (Settings>Battery>PowerMaster>Battery Care) that slows down the charging speed if you charge overnight. Does it really improve battery life? I don't know. Maybe charging it slowly (which is what this feature does) all the time is better... the "problem" is that this phone's battery is big and it can take over 2 hours to charge it from a low battery state. Anyway, don't forget to use and enjoy your phone. Phones don't last forever.