The main problem with the Apple iPhone is battery consumption, and what every iPhoner requires is longer battery life, or some extra volume and the answer to the problem comes from Santok with their iPhone compatible power pack.
The iPhone Power Pack features a rechargeable Li-ion polymer battery with the ability to bring up to 7 hours of talk time, 20 hours of music playback time or 200 hours of extra standby time.
You will also find two 1W stereo speakers which increase music or video audio output, and all encased within a premium flip design case that has a camera hole, and also offers up protection for your Apple iPhone.
Source — Santok