About this replacement
Garmin vivosmart 5 — 3.85V Li-Polymer Replacement Battery (361-00156-00)
This 3.85V, 110mAh lithium-polymer cell is a direct swap for the battery inside the Garmin vivosmart 5 fitness tracker. It fits the compact wristband platform that tracks heart rate, sleep, stress, and daily activity. Voltage and capacity match OEM spec (361-00156-00) exactly.
- vivosmart 5 platform fit: The vivosmart 5 uses a fixed connector and BMS handshake tied to the 3.85V cell architecture. This replacement matches that voltage rail and the physical footprint (25.20 × 12.00 × 3.60mm), so the BMS accepts the new cell without flagging a mismatch.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the vivosmart 5 platform. The BMS completed charge acceptance without error flags, and the fuel gauge IC re-registered state-of-charge correctly after a full charge cycle from near-zero.
- Post-swap charge requirement: After fitting this cell, place the watch on its magnetic charger immediately and charge to 100% before use. The fuel gauge IC on the vivosmart 5 loses its reference point when the original cell is removed and cannot recalibrate without one complete charge cycle from near-zero on the new cell.
Why the vivosmart 5 magnetic charger fails to register after reassembly
The vivosmart 5 charges through spring-loaded contact points on the rear housing. During a battery swap, those contacts can shift slightly if the rear cover is not reseated flush and square. When alignment is even fractionally off, the charger pins make intermittent contact and the watch will not enter charging mode. Re-seat the rear cover with even pressure around the full perimeter, then confirm the charging indicator appears within 10 seconds of docking.
Watch not pairing to phone after battery replacement
Removing the battery clears the active BLE session between the vivosmart 5 and the Garmin Connect app. The watch and phone each retain a stale pairing record that no longer matches, which causes the connection to fail silently. Delete the vivosmart 5 from your phone's Bluetooth settings and remove it from the Garmin Connect device list. Then re-add the watch through the Garmin Connect app as a new device to re-establish a clean pairing.