I purchased one of these at at 650 mah at my local b+m vape shop over the weekend. It seems to be satisfactory so far. Though the battery life seems alot shorter than my previous generic ego twists. It last me about half a day while my other cheapos lasted almost a full day. Is cijoy a generic battery company also? Does anyone here own one of these? Is my battery life consistent with others. I paid $49 bucks for it which I know seems high but it is lifetime gauranteed. Guy said as long as its not lost I'll always get another one regardless of how I screw it up. Did I get ripped? Is this an inferior product? Any thoughts would be appreciated.