MiPow Power Tube 4000 - External battery pack - Li-pol - 4000 mAh - black - for Apple iPhone/iPod

This little power supply is great. It works just like directed and is awesome allowing you to charge your battery on your device no matter what you may need it for. It is really easy to use and I believe that it quickly charges and allows plenty of time to charge devices. The unit is bult solid. At first I thought the little wire that connects the main body to the femal USB end would break easily, but I believe that this is built pretty solid. Excellent unit overall. Great Buy!

Bought this for my daughter to take to camp because there was limited access to electricity to recharge her phone. It gave 2 1/2 charges for her iphone. Easy to use. Just remember to unplug and turn it off when the charge is complete. The directions say if left hooked up it will continue to drain power from the charger. Worked perfectly for us. It continues to be used for other occasions as well.

Got this to take with me on long bike rides. It fits inside my jersey pocket and stays there. Have only had to use it once so far and it charged my iPhone 4S quick.

I think we probably would have loved this little backup battery except for one small problem. It was suitable for a iphone 4 not for the new 5 or 5c. Besides that, I think it would have worked wonderful. Unfortunately we had to return ours.

I haven't used it a lot yet, but it definitely supplies extra power for my itouch. Wanted it for vacations & haven't been on 1 yet, but I imagine it will fit the bill! Should be able to have power on long plane rides!