vívoactive - Replacing the Heart Rate Monitor Battery
Garmin Fenix 3 - Garmin: Replacing the Battery in your Heart Rate Monitor (HRM) The CR2032 batteries in your HRM-Run, HRM-Swim or HRM-Tri straps will last approximately 18 months, depending on use.
vívoactive - Putting On the Heart Rate Monitor
Garmin HRM-Dual™ | Heart Rate Monitor with Chest Strap