I use a AW 2000mah and it lasts me usually about half a bottle... I just ordered 2 AW 1600mah as they have a slightly better fresh voltage curve for low ohms according to all the charts I have seen.. I go past that really good fresh battery vape very quickly on the 2000mah and its an ok vape afterwards. Normally I place new battery at 5:30am, will last me through work till about 4 pm then change for that great vape again after I get off work. Weekends its like 3 or 4 fresh battery changes a day! I vape alot on the weekends, more than a bottle a day sometimes!