About this replacement
Garmin Vivoactive HR — 3.7V Li-Polymer Replacement Battery (361-00090-00)
This 3.7V, 180mAh Li-Polymer cell is a direct swap for the original battery in the Garmin Vivoactive HR smartwatch. It fits the wrist-worn GPS fitness tracker that runs continuous heart rate monitoring, activity tracking, and smart notifications. Dimensions are 36.40 × 19.80 × 3.20mm — match these before ordering.
- Vivoactive HR fitment: The Vivoactive HR uses a dedicated battery bay sized for this exact cell profile. The flex connector locks to the same board header as the OEM unit, so no adapter or re-pinning is needed.
- Bench tested on actual hardware: We ran this cell on a Vivoactive HR with GPS active and continuous wrist HR enabled. The BMS accepted the charge handshake without error on the first connection and held steady voltage through full charge and discharge cycles.
- Fuel gauge recalibration after swap: After fitting this cell, place the watch on its magnetic charger immediately and charge to 100% before first use. The fuel gauge IC on the Vivoactive HR cannot set an accurate reference point without a complete charge cycle from near-zero following a cell swap — skipping this step causes false low-battery readings.
Why the Vivoactive HR shows 0% straight after a battery swap
The Vivoactive HR uses a coulomb-counting fuel gauge IC that tracks charge relative to a stored reference. Removing the old cell clears that reference entirely. When a new cell is fitted, the IC has no baseline, so it defaults to 0% or reports an incorrect state of charge. Charging to 100% immediately after installation resets the reference register and restores accurate percentage readings. Do not skip this step even if the watch powers on and shows activity.
Watch not pairing to phone after battery replacement
Removing the battery kills the active Bluetooth session stored in the watch's memory. The phone retains a paired device entry, but the watch no longer recognises it as an active bond. Go into the Garmin Connect app, remove the Vivoactive HR from paired devices, then re-pair from scratch through the watch's settings menu. This takes under two minutes and fully restores notification and sync functions.