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Kmashi charger- Unboxing: the unit arrives is a sturdy cardboard box, with a manual translated into very good English, a warranty card in mostly Chinese, and a white micro USB cable about 20" in length. I was pleasantly surprised by the quality and rounded molding of the cable. The battery unit itself is shipped in anti-scratch plastic, and has a shape that slightly rounds in the long edges of the case, which I found made it easier to slip into a pocket without edges sticking out, nor being uncomfortable when sat on in back pocket. There are also long scalloped indentations along the edges to assist in grip. I couldn't quite see these details from the photos provided on the product page. The length of the USB cable allows for the battery pack in a back pocket while the phone is in the front easily, or to pull out and use without pulling on the battery pack, without being so long as to be obnoxious. Not quite long enough to hold phone to ear for me at 6' tall, but close! The unit arrived partially charged, with two of the four blue LED charge indicators showing up to 50% charge, according to the manual. It took approximately 5 hours to reach full charge, with all four LEDs solidly lit, using a 2.1 amp iPad 2 charger. Using your average phone charger, which typically range from .5A to 1A, will obviously extend the charging time required. The following informal tests were done using the 2.1 amp output. Note that this unit will not charge from the USB output while being plugged in and charging itself, as I had hoped, and as some of the other battery packs are able to do, working as higher powered USB hubs. I did not see this mentioned in any other reviews, so I hope it is helpful. I started charging my Nexus 4 with it at 32%, and it immediately showed progress, at almost 1%/minute. I was using (battery hog location-based game) Ingress, browsing, and video during charging as well as writing part of this review; it may be significantly faster if just charging alone. GPS was on, wifi was off. Also of note, my Nexus has a worn battery (2100 mAh), hence the purchase of this Kmashi external battery while waiting for a new internal Nexus battery to arrive. After 1 hour, the phone was at 58%, and all four LEDs were still showing, meaning I still had at least 76% charge left, if not more. At an hour and a quarter, the phone was at 63%, and all four LEDs were still lit. At two and a half hours, the battery was completely full, and all four LEDs were still lit. I then plugged the battery pack into my iPad 2, which was at 63% charged. I was not actively using the iPad, but WiFi, GPS, and Bluetooth were enabled. Cellular data/radio was turned off during this time. At 2 hours, the iPad 2 was at 90%, and three LEDs were lit on the Kmashi. At 3 hours, the iPad 2 was at 100%, and two LEDs were still lit on the battery pack. It may have been slightly less than 3 hours to reach full, but this gives you an idea of the charging ability for a tablet the size and battery capacity of the iPad. Next, I plugged in my iPhone 4 at 38% charged. I was not using it at the time, but WiFi, GPS, and Bluetooth were enabled in addition to 3G cellular radio. 20 minutes brought it up to 55%, with 2 LEDs still lit on the battery pack. At 1 hour, the iPhone read 88%, and battery pack was finally down to 1 LED. I then plugged the Nexus 4 back in with it at 52%, and charged the phone while running errands on my commute home, approximately an hour of plugged in time. Upon arrival home, I plugged in not only the Nexus 4, but an old Droid X that I use as a dash cam, with the Droid going into the 1 amp output. The Kmashi battery pack had slowed its rate of charge slightly, but continued for a further 45 minutes, at which point the last LED began blinking. The battery pack continued charging both phones, however, for a further 10 minutes or so before shutting down, having served 4 devices valiantly all day long! I know this test is far from scientific, with none of the readings and math I enjoyed reading in other reviews. Rather, it's a real-world report and review on what to expect from the Kmashi 10,000mAh external battery pack. Being one of the lower-priced options, I had moderate expectations that were actually surpassed so far. I understand that a few more charge/drain cycles should improve performance even more. Despite the lack of science, if this review has been at all helpful, please click so below. Thanks! Notes: Have not noticed any increase in temperature of the unit while charging itself, or using it to charge other devices, indicating to me efficiency of operation as opposed to energy lost through heat. I've also noticed that this pack will shut itself off once the device is it is charging has reached full capacity, indicating IC's that are providing smart functions not mentioned in the manual. You do have to press the power button, located next to the level LEDs on the side, to begin charging. I've seen this be an issue for some reviewers of other battery packs, and I've forgotten once or twice so far, but don't find it to be an issue. Holding the button down for 2 seconds turns the unit off, or it will shut down automatically as noted above. The button has a solid feel with a firm but quiet click. I would definitely recommend this battery pack so far as an option to the fancier and higher-priced aluminum clad, oled screen equipped alternatives. Solid build, design and performance. I was NOT provided a sample by anyone- I bought the dang thing myself like most everyone here does. ;-)