We aren’t gonna tell you to stop checking Facebook on your phone every thirty seconds, no matter how paranoid we think you are for doing so. Seriously though, if you’re a power user, it’s very likely that you’re running out of juice before the end of the day, no matter what size of battery your current device has. If you’re an iPhone or big-label Android phone user, there’s an extended-battery case waiting in an Amazon warehouse with your name on it. For us Windows Phone buffs, however, our best bet is to leave Battery Saver on and dial down the usage.
Mugen Power hopes to change this with a lineup of battery cases for Nokia’s Lumia 820, 920, and the HTC 8X. In exchange for a noticeably bulkier device, you will likely get several extra hours on top of what the standard phone’s battery can provide alone. One might also use such a case as an emergency charger to keep in a backpack pocket, for only temporary use. Also, since the 820 has a removable back cover, it is likely Mugen Power can develop a case with a fairly small footprint when compared to adding a full second battery to other, non-removable-cover devices. There is no word on pricing or release dates as of now.