Empty batteries are a thing of the past.A high performance detachable solar panel provides charging power for batteries for diverse electronic appliances on every trip. Ideal for charging smart phones, tablets, ipods, speakers, MP-3 players, etc. when there is enough sunlight. These solar cells have an efficiency of 22 % and thus get more out of the sun rays than standard cells. The solar cells are protected by a scratch resistant surface.The solar panel is optionally removable, and can be stored in the backpack’s spacious compartments. Solar panel 6.5 Watts, 6V 1.1 A.this backpack is perfect for daily use, travel, and outdoor activities including backpacking, trekking, mountaineering, fishing, biking, etc. It’s light weight and the superior designed support points provide optimal comfort.