Instapark D5600 Pocket-size 5,600 mAh External Battery Pack & Charger with USB Port for iPad2, iPad,

• High-capacity 5,600 mAh Li-ion rechargeable & portable battery pack, powerful enough to supply 28 hours of movie time on iPhone 4 or 8.5 hours on an iPad
• Built-in USB charging port for charging device such as iPhone, iPad and other USB compatible mobile devices
• Compatible with virtually all USB compatible cell phones, tablet computers, MP3 Players, digital cameras, handheld game consoles & etc.
• 4-LED battery level indicator & automatic switch on when a device is connected
• Measures only 2.75 X 2 X 0.75 inches and fits easily into any pocket

It appears that I am the first reviewer for this product. I bought this battery to recharge my iphone 4s on backpacking trips. I was originally looking for a lightweight solar charger but I discovered that the small solar chargers are to weak to charge an iphone (and also expensive) so I started looking at external batteries. This one is the smallest and lightest I could find, smaller than a pack of cards and easily fits in the palm and only about 5 oz in weight. It comes with a USB charging cable so you can charge it from any device with a USB port, but it will take a lot longer to charge from a laptop than a wall outlet. I use the USB-to-wall plug adapter that came with my iphone and I can charge the battery fully in about 2 hrs. As for the 5,600 mAh claim I'm not totally convinced. My phone has a 1,500 mAh battery so it should be able to charge completely 3 times and then some, but I have only been able to get about 2 and a quarter charge. The battery has four indicator lights that come on when you push a button to tell you how much charge is remaining (100% 75% 25% 5%). I'm assuming that if two lights are lit up that means you have between 25 and 75 percent left. The battery has a smooth mat coating that feels silky to the touch, but this has started to bubble up on one end, possibly due to being in a hot backpack. All in all, for $30 this is a great little battery!

Buy Instapark D5600 Pocket-size 5,600 mAh External Battery Pack & Charger with USB Port for iPad2, iPad, Now

Used it in my trip to Russia. One full charge translates to about 80% battery for my Galaxy Tab 2 7.

Only used it two times, one month apart, but it seriously helped on the plane.