The PocketBase Kit from Switronix provides a comprehensive powering solution for your Pocket Camera. It attaches on the bottom of the camera and powers the camera up to 5 hours with two LP-E6 batteries, while at the same time charging the camera's internal battery.   

https://www.bhphotovideo.com/c/product/1007270-REG/switronix_pkt_basek_pocketbase_battery_holder_with.html