http://www.zdnet.com/article/15-day-smartphone-battery-life-oukitel-says-its-android-k10000-just-keeps-on-keeping-on/

10.000mA battery huh and 240$, sounds interesting but obsessively not a top spec phone.

There are many very good sub 10.000 baht phones on the market now and I just don't get it that some shell out 25k baht on a phone man, I really don't, you can get a fairly good lap top PC for that money.

Whether you would get 15 days usage would totally depend on if the device you are powering only used 667ma per day. Most smartphones probably have around a 2500ma battery in them and not uncommon for a person not even to get through one day of usage. It would all depend on your smartphone, what apps you have running, how long your look at the display, using Wifi or 3G, GPS on or off, etc...etc...etc.

But I bet their 15 day usage estimate based on their "normal usage" estimate, which they don't define what normal usage is, would be a bare bones usage like maybe only to make an receive short calls, some SMSs, just very little usage of the phone, etc.

That's why USB battery packs are so popular.