This is a review of UNU Unity Battery case for Galaxy S5. UNU Unity Battery Case for Samsung Galaxy S5 | uNu , also available on amazon Amazon.com: UNU Unity Samsung Galaxy S5 Battery Case - Rechargeable External Protective Battery Case [Black/Black] for Samsung Galaxy S5 Compatibles with All Models Samsung Galaxy S5 [A.K.A Extended Power Bank Battery Pack Charger Case Cable]: Cell P The idea of battery case is not a new concept. A few years back, it used to be popular in a form of external battery attachment molded into a bulky case with hardly any protection. Then, this idea was improved by using custom shaped batteries (double or triple capacity) sticking out of the original smartphone battery pocket, and using a custom plastic or TPU shell as a battery cover for a basic protection. Unfortunately, both of these approaches affected the thickness of the phone (by more than doubling it), phone protection was reduced, and often NFC support built into OEM battery was not available. UNU decided to improve this concept with a very clever solution. Here is what I found. Arrived in a very simple package, the front is an open display under the cover revealing a slick look of what appears to be a typical smartphone case. You wouldn't even think for a second it was a battery case until you flip it over to see a description of UNU Unity Series with a detailed list of features, pictures of assembly, and benefits of additional hours by doubling the battery capacity. Yes, that's exactly what this battery case does - it doubles the capacity of stock 2800 mAh battery and provides a pretty decent protection by surrounding your Galaxy S5 in ultra-slim soft touch case. Let me first start with a battery itself. As a standalone piece, there is a custom chassis with UNU's own 2800 mAh battery which goes into battery compartment of S5 instead of your OEM battery. It has an identical footprint and thickness comparable to OEM S5 battery with an addition of chassis on the top where you place your original S5 battery. This way both of the batteries are connected together, charging from the same S5 pins, and appear to Galaxy S5 as a single 5600 mAh battery tracked in your notification bar where you usually see battery percentage. This integration is completely transparent to your phone just like with any other extended battery. The case is made of two parts, the battery cover and the bumper. This is where UNU's design stands out from the crowd. Instead of a bulky TPU case with loose fitment or minimum drop protection, you actually get a quality back cover made out of durable PC hard shell material with a soft touch finish and an interlocking bumper that snaps securely to protect edges of the phone and provide a decent front lip which enables you to place the phone face down without touching the display. I have a tempered glass on my S5 and it worked well with this case, and I still had clearance to place the phone face down. Regarding the case itself, every port opening had a precise cutout and perfect alignment. Micro-usb port had enough clearance to flip the cover open, there was plenty of room to access heart rate sensor, and power/volume buttons had a nice tactile response. Having a rounded shape of the back cover made this case feel very slim in your hand, yet still providing a secure grip. Overall, the case and the battery is approximately 78g, and if you take into consideration removal of original S5 battery cover which is no longer used in a new assembly, the total weight increase should be under 70g. Also, due to original battery being placed on top, you still get access to its built in NFC antenna. Regarding the performance, though UNU provides a reference of how many additional hours you will get - I honestly don't want to get into these details because we all use our phones differently. If I'm going to say, "oh, I got 10 more hours of game play" it will be relative to my specific phone use with everything else I'm running on my phone and all other background processes. It's hard to do apple-to-apple comparison between two phones even of the same model when it comes to battery life unless you have a carbon copy image of every app and setup. The bottom line, you are doubling your battery capacity so as a minimum you should see 75%-80% increase in additional use hours (nothing is ideal due to efficiency). Overall, I was very impressed with a design concept of this battery case, with its innovative approach to double the battery capacity, and with attention UNU paid to the case design with an ultra slim form factor which feels like a regular case rather than a bulky battery add-on. I know it's a bit pricier than other extended batteries, but considering that it's not just a double battery but also a quality case, I think price increase is justified. So if you are looking to double battery life of your S5 and don't want to double the weight or bulky appearance of your phone, I highly recommend to check out UNU Unity case for Galaxy S5. Here are the pictures.