Mophie has released the Juice Pack Air for the iPhone 4. The $79.95 battery pack for your iPhone is the latest offering from Mophie’s popular lineup. A lot of people swear by these power packs for their phones that let them both charge and sync through a USB cable, in addition to doubling battery time.
I’ve had a love-hate relationship with my original Mophie Juice Pack. The first model they ever released had some issues with charging, most notably the inability to stop the device from charging my iPhone. If it was plugged in, it was charging. That being said, it also got me out of some serious binds on a European trip, and an east coast road trip, so it clearly serves its purpose. They’ve obviously addressed the problems that have come in the earlier editions by adding power buttons, and a switch that lets you start and stop the charging with the flick of a button.
You can check out their lineup on Amazon.