As one of a series of new charging accessories from China's Mipow, the Power Tube 2200 ($39) is a certified iPod and iPhone battery pack in a distinctive aluminum tube shape. With an auto-switching outbound and inbound charging port on one end, Power Tube 2200 has a 2200mAh battery inside, capable of fully replenishing any iPhone once, with one or more charges per iPod model as well. You need to refuel the Power Tube 2200 with a full-sized USB connector,…
