So far i am looking at the Alien, the Ijoy PD270 and the Eleaf Ikonn 220w. Kinda on a tight budget so any suggestions? Maybe i'm missing better options? I currently run a Ipower 80 but need something else as it's not enough to last a full day and would like to get one with replaceable batteries. Do not have an external charger just yet but will purchase hopefully shortly after mod. Thank you in advance.