After the purchase I have the solar panel tried immediately with iPad and iPhone. When the sun shines both devices are loaded, under an overcast sky, it is enough to iPhone for a trickle charge. The latter I have not yet tried using the Ipad. The time now is 08:05 Uhram morning on Norderney, completely overcast sky and my iPhone battery has 28% charge level. Not one percent is lost, even though I just rumsurfe the internet and write this review. My iPhone is loaded by the panel in direct sunlight within 2.5 hours from 20 to 90%. Somewhat misleading, I found the recommendation that the power battery equal to order with. Here I understood that this can be also loaded with the panel, but this is incorrect. I have the panel with the strongest sunshine over 4h connected to the Power Battery: No charge success. If one is charging the battery via power outlet, and then go on tour with it is the panel and the power battery a perfect symbiosis. Load Cell with the Panel and recharge during the day or night as needed in the tent again with the Power Battery, so I came along without even have to use a complete current week with canoeing on the Rhine.