I have the original stick batteries I ordered. I use my larger batteries all the time now- however
When I smoked I always kept a pack in my left pant pocket. When I got my starter kit, it had the carrying case that holds the smaller batteries. I keep it in my pant pocket still (must be psychological lol). But it has bailed me out when I have forgotten to charge my batteries or havent had a chance, and I just toss my smileomizer or tank on until I can get home and grab a fresh battery.