hey as you can see I thought I was having major problems with this thing before, Now I love this mod, I would use the Ijoy 20700s 3000mah I know they are rewrapped but they were tested by mooch they are good batteries its only a single battery mod but i can vape down to 30% battery life before I decide to change and charge batteries, this is only depending on builds and how you vape though Im a chain vape kinda guy and I cycle through 3 batteries all day but more normally for me is 2 batteries a day. .28 ohms is too low of a build for the 75c Ideally you want a single coil at .40 - .60 I mean you can still vape dual coils but deff at a higher ohm then that or else your batteries will drain super quick even on Ijoys. Took me about two weeks messing around thinking it wasnt me and it was the mod before I got it to work like I wanted it to and its the best mod I own sorry for the ongoing response im at work, good luck