Today only, SharkStores offers the PowerPatch Battery Case for iPhone 4 / 4S in White Leather, model no. PP12582, for $54. Coupon code "3DEALNEWS3" cuts it to $51. With $4.95 for shipping, that's the lowest total price we could find by $9. This battery case purports to increase stand-by time by up to 300 hours. It features up to 7 extra hours of talk time, up to 6 extra hours of web access, up to 10 extra hours of video viewing, and up to 40 hours of extra music playback.