I've had this for about 2 years and it works great.  Actually when I was playing my PS4 (across the living room) my controller died.  I didn't have like a 10' cord, so I figured hey I'll use my back up battery (aka this thing).  Plugged in the controller, hit the button, and BOOM!!!  Hours of ps4 gameplay without having to take a break or sitting 2 feet from my tv.  Also this worked great at charging my phone and tablet whenever I was out and about.  It has a flashlight on it too, just in case.