First thing to do with the Mini is run it wide open for 15-20 minutes. Burn in, so to speak. And careful with the battery. It's the same type my Vapolution uses. It's easy to screw up the electrical connection where the flimsy cable attaches to the battery pack. It's not that it's poor workmanship or design, it's just not designed to be used on an external pack that you can't attach to the unit it's running.