My first mod is a flashlight mod, with CR2's. I used CR2's from local store Energizer E2's. they worked great, lasted 7 days. I built my mod 3 days after you posted this thread. I ordered my batteries the very next day. (December 19Th)... today is January 18th... I still don't have my batteries. They will have zero charge left in them by the time I get them. LoL! well? at least i have a charger! Happy vapin' with your magnum mod. I hope you like it.