GoPro Hero 3 and 3+ Battery Eliminator Power Adapter Cable-W
Amazon.com : Complete AC/ DC Power Kit for GoPro Hero 3+ and Hero 4 (Not compatible with Hero 3 & older) Includes USB Power Cable,Water-resistant Backdoor Passthrough,and 3 Adapter Plugs (US &
Core SWX GoPro Battery Eliminator with Wall Adapter DV-GP3-USBPS