4200mAh External Battery Backup Charger is fantastic as a short road trip battery. It's bigger than I want to carry when flying but is perfect for charging. Right now Moving Life has their 4200mAh External Battery Backup Charger Case Pack Power Bank for iPhone 5 5s 5c for cheap price. You'll just need to visit the site.
Innovative Two Piece Slider Design for easy installation and full body protection of your iPhone,charging and protecting: function 2 in 1. On/Off switch with One-Touch smart design easy to operate,Built-in kick stand for Video Watching. Perfect cutouts allow access to all cameras, microphones, sensors, controls and most importantly headphone jack. Side extra USB port can help do other emergency charging for other USB devices when needed.