Here is a portable device that charges your wireless headphones, fitness trackers, and wearables. The mophie Power Capsule comes with a 1400 mAh battery and space for your gadgets. You also get pass-through charging while the Power Capsule is connected to a power source. It has an output of 1.0A.
The Power Capsule is compatible with Fitbit Flex, Apple Watch, Jaybird, Beats by Dr. Dre powerbeats2, and a bunch of other popular wearables. Costs $39.95.