Last week Mophie announced and launched the Juice Pack for the Samsung Galaxy S4. \u00a0If you're familiar with the Mophie brand then you know it's a battery pack case that slips around the handset.\r\n\r\nThe Samsung Galaxy S4 Juice Pack is finished in a wonderfully, almost velvety smooth rubber that provides the case with a soft touch, but is anything but sticky (just in case you were wondering if it will get stuck in your pocket).\r\n\r\n\r\n\r\nLike many if not all of Mophie's battery cases, there are 4 LED lights to indicate remaining battery, an on\/off switch, and a button to check the remaining juice, all of which are found on the back of the case. \u00a0When the case is turned "on" a green dot is revealed. \u00a0In the "off" position a red dot shows. \u00a0For clarity's sake neither of these are viewable in low or no light scenarios. \u00a0Push the button and the LED lights will illuminate displaying how much juice is left in the case.\r\n\r\nTo charge the Juice Pack for the Galaxy S4, Mophie includes a microUSB cord, but you'll need to supply your own AC adapter - the one that came with your S4 should suffice. \u00a0Moreover, when the case is plugged in and the phone is "docked", the Juice Pack will charge both itself and the Galaxy S4. Compare that with any of the best Samsung Galaxy S4 cases that offer rugged protection, style, and more battery life.\r\n\r\n\r\n\r\nThere are also the requisite pass-through buttons for the volume and power\/lock switch - all work as if they were the buttons themselves. \u00a0Lastly, there are a set of ports located throughout the Juice Pack case to address the camera, mics and infrared sender. \u00a0At the bottom of the face of the Juice Pack there are also a set of slits. \u00a0One is designated to the mic and the other to the S4's speaker. \u00a0The mic seems hardly impacted, where as the speaker's clarity is every so slightly reduced by emitting less treble.\r\n\r\nInstalling the Juice Pack is a simple affair. \u00a0Just simply remove the top portion of the case, slide in the Galaxy S4 and if done correctly it will fit snuggly and if not almost perfectly into place. \u00a0Adhering the remaining top portion is a bit more fiddly affair, but easy enough as this particular Juice Pack's design is easier to line up the two piece. \u00a0However, removing the Juice Pack requires that you grip the corner edges and pull from the top. \u00a0At first I pulled from the camera port, but quickly discovered that that section is actually attached to the lower portion of the Juice Pack. \u00a0This isn't to say it's difficult, but compared to Mophie's other Juice Pack cases it will take you a few trials to determine where to position your hands such that you're not pointlessly pulling on the case. \u00a0Nevertheless, this will probably be a moot issue since you'll likely leave the Juice Pack attached to the Galaxy S4 as it adds all around protection to the phone's back and bevel.\r\n\r\n\r\n\r\nBut with that protection comes the caveat of size. \u00a0 The Galaxy S4 Juice Pack doubles the weight (it weighs 4.6oz, the S4 4.59oz) and thickness (the Mophie Juice pack is .66-inch, the Galaxy S4 .31-inches) of the Galaxy S4.\r\n\r\nSo that begs the next question: how much juice can the Juice Pack provide to the Galaxy S4? \u00a0From a charge of 10% I was able to return my Galaxy S4 to 67%. \u00a0With a capacity of 2300mAh, just 300mAh shy of the Galaxy S4's battery, I had hoped to achieve a total\u00a0recharge of 80%. \u00a0In my experience, largely based on using the iPhone Juice Packs, Mophie's battery cases have delivered at least an 80% incremental charge. \u00a0And to be candid, this was with no active use - screen off and connected to LTE.\r\n\r\n\r\n\r\nSo is the Juice Pack for Samsung's Galaxy S4 a disappointment? \u00a0In short order, no. \u00a0The size is probably the Juice Pack's biggest caveat, but with that comes protection and almost 60% added battery life, something all Galaxy S4 owners will take with open arms. \u00a0 Mind you, Mophie did promise an 80% incremental charge, so it only seems fair that they'd discount the asking price of $99.95 by a proportional amount, right?\r\n\r\nOf note, an extra S4 battery, which adds no protection, costs $40 from Amazon, and without a shred of doubt doubles the S4's battery life.