Mophie has finally announced its battery case for the iPhone 5: the $80 Juice Pack Helium. We've previously vouched for Mophie's portable USB batteries, but they had yet to release a battery case for the new iPhone form factor. Apple's iPhone 5's built-in battery has a 1440 mAh battery, while the Juice Pack Helium will effectively double that with 1500 mAh more. I've found on a typical day, my iPhone 5 with LTE turned on will drain to about 40% by the end of the night, so this battery pack would likely extend that to two full days of use. The Mophie was very popular at technology conferences like SXSW last year, and the Juice Pack Helium's February 14th release date mean it'll be out just in time for this year's SXSW and GDC. Oh yeah, that's also Valentine's Day.