How to replace the battery GARMIN Fenix 3 HR - YouTube
Garmin Fenix 3 HR - Battery Life - YouTube
Battery for Garmin Fenix 3 HR Smartwatch 3.7 V Li-Polymer: Amazon.de: Electronics & Photo
Amazon.com: Synergy Digital Smartwatch Battery, Works with Garmin Fenix 3 HR Smartwatch, (Li-Pol, 3.7V, 300mAh) Ultra High Capacity, Compatible with Garmin 361-00034-02 Battery : Electronics