https://www.engadget.com/2010-08-26-mili-powerspring-4-doubles-the-battery-life-of-your-iphone-4.html
Mili PowerSpring 4 doubles the battery life of your iPhone 4
Aug 26, 2010 - There's a big difference between the iPhone 4 and Galaxy S. No, not iOS vs. Android 2.1 or even Retina vs. Super AMOLED. We're talking batteries: one is...
the batterymilidoubleslifeiphone