UPDATE: 9/28/2016
I've had some problems with this recently. I'm not sure if it is the battery yet, or the age of the phone but it seems to lose contact with the phone every once in a while, which causes the phone to turn off. It got so bad that I had to go back to original battery (and that issue stopped right away). I'll give it another shot soon, but for now, I had to stop using this because I need a phone that stays on while I am in the middle of using it.... Will update again once I give it another shot, but for now, lowered from 4 stars to 2.

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Original Review:

This is a pretty good case with an extended battery for the Galaxy S5 phone. This case replaces the back cover of your phone, and replaces the original battery with a larger one. At first it seemed to be off and not working as far as the percentage indicator goes, but after several days of use, it was clear that the battery was definitely lasting a lot longer. I can pretty much go double the time that I used to with the original battery, and on power save mode, even longer (even though the remaining battery life estimate may not be accurate).

My only complaint is that the case part of the item doesn't provide much protection to the screen. If would be nice if it had a bigger lip over the edge of the phone.  Size-wise it is not too much bigger than the original phone (considering that the battery is double) and I think it actually makes it easier to hold the phone.
UPDATE: 9/28/2016
I've had some problems with this recently. I'm not sure if it is the battery yet, or the age of the phone but it seems to lose contact with the phone every once in a while, which causes the phone to turn off. It got so bad that I had to go back to original battery (and that issue stopped right away). I'll give it another shot soon, but for now, I had to stop using this because I need a phone that stays on while I am in the middle of using it.... Will update again once I give it another shot, but for now, lowered from 4 stars to 2. ----
Original Review:

This is a pretty good case with an extended battery for the Galaxy S5 phone. This case replaces the back cover of your phone, and replaces the original battery with a larger one. At first it seemed to be off and not working as far as the percentage indicator goes, but after several days of use, it was clear that the battery was definitely lasting a lot longer. I can pretty much go double the time that I used to with the original battery, and on power save mode, even longer (even though the remaining battery life estimate may not be accurate). My only complaint is that the case part of the item doesn't provide much protection to the screen. If would be nice if it had a bigger lip over the edge of the phone. Size-wise it is not too much bigger than the original phone (considering that the battery is double) and I think it actually makes it easier to hold the phone.