I just received this product and putting it to the window, not even gray time it loads. Small flat, no documentation, so be aware that there is a small on / off button to start charging the device connect. It loads the Samsung Galaxy Tab 10 March 'from the USB 2A. The protection of the solar plate screen has bubbles everywhere and I do not think it takes away. I will contact the seller for it. -> Addition on 11/07/2014 Back seller on the bubbles on the screen: this is not serious but can be removed this protection if we want. After over a month of use, the charger has a little trouble fully charge my Samsung Galaxy Tab 10 March '. It was after a while, we must turn it back on for it to continue to load. Loading the charger via the sun can be useful but it is extremely slow (normal with 30,000 mAH. I load via USB to my PC and then recharge from 0 to 100% takes about 20h. It is not possible to charge the charger and charge the same time unit which can be damage. -> Addition on 11/20/2014 The charging device is a slow beginning. The charging my Samsung Galaxy Tab 10 March is also longer at the beginning and from time to time, charging stops in the middle. We must press the button again to resume loading.