The Solar backpack is a simple high quality backpack, usually made of 1,680-inch nylon with small solar panels attached. A new technology known as thin film solar panels is used to generate electricity from the sun while keeping the weight around 3 lbs. The entire backpack 5 pounds Currently, there are two major manufacturers of solar backpacks, photovoltaic systems and Eclipse Gear. Their backpacks have similar features. One is a little cheaper, while the other generates more power. The two backpacks are designed to charge handheld electronics such as mobile phones, PDA, GPSs, and digital cameras. They are not designed to charge a laptop. Laptops usually generate more current than backpacks, so eventually the battery pack runs out completely. Portable handheld electronics will not consume that much power, so the backup battery will remain charged. A 4,400 mAh, 3. The 6 Volt lithium ion battery, along with a wide range of adapters, is perfect for almost any personal electronics you may have. You can charge backup batteries in three different ways, through thin film solar panels, AC adapters, or DC cigarette lighter adapters, all of which are included. There is a big backpack for both backpacks. 850 cubic inches of storage space and many pockets for storing MP3 players, mobile phones and water bottles. The Voltaic backpack can even handle a 3-liter water bag with pipes through the wire channel of the bag for hands-free. Solar backpacks are available to almost anyone, but they are especially useful for hikers, campers and hunters. How many stories about people walking into the wilderness getting lost? Some are saved by phone calls, while others are powered off when the phone or GPS is most needed. These backpacks are great, they rely on small electronic devices such as mobile phones, GPSs, and digital cameras, but will not be close to charging power in a few days. Digital landscape photographers, off-road skiers, cyclists can make the most of this great new technology.