Source: http://gizmodo.com/turn-your-iphone-charger-into-a-portable-backup-battery-1613449223/+whitsongordon
Even carrying your iPhone's charger everywhere you go doesn't guarantee you'll be able to keep your phone running all day. Sometimes outlets can be hard to find, and for those times the NomadPlus is here to help—transforming your iPhone's standard charger into a portable 1,500 mAh battery for back power on-the-go.
Shipping in late November for just $39, the NomadPlus simply requires you to insert the compact AC adapter that came with your recent-generation iPhone, immediately giving you a portable charging solution with enough power to bring a dead smartphone about 70 percent of the way back to life.
When plugged into a wall it charges a connected device first, and then itself. So come morning your smartphone is ready to tackle the day, and then the evening on top of that, even if you can't get access to an outlet. [Nomad]