Garmin fēnix 2 010-01055-15 Replacement Battery 3.7V 1200mAh

Garmin fēnix 2 / GLO Series — 3.7V Li-ion Replacement Battery (010-11935-00)

This 3.7V, 1200mAh Li-ion cell replaces the OEM battery in the Garmin fēnix 2 smartwatch (010-01055-15), GLO, and GLO 2 GPS receivers (010-02184-01). It matches the original cell's dimensions at 53.00 × 33.90 × 5.70mm, fitting the existing battery bay without modification. Voltage and capacity are identical to factory spec.

• fēnix 2 and GLO platform fit: These models share the same battery footprint, connector pinout, and 3.7V supply rail. The fēnix 2's GPS and heart-rate circuitry and the GLO's Bluetooth receiver module both operate from this common cell without any BMS handshake conflict.
• Bench tested on actual hardware: We cycled this cell through charge and load on a fēnix 2 unit. The onboard BMS accepted charge from the standard clip charger without fault codes, and voltage held steady under the combined GPS radio and display load.
• Cold-start satellite acquisition after fitting: After installing this cell, power the watch on outdoors and let it run a full cold-start GPS fix before heading out. A cold start after full power removal can take 5–10 minutes for first satellite lock — subsequent warm starts will return to under a minute once almanac data is cached.

GPS accuracy reduced when battery charge drops below 20%

The fēnix 2's GPS receiver draws its highest current when maintaining continuous satellite lock during active tracking. At low charge, the firmware throttles receiver sensitivity to protect the remaining cell voltage. This shows up as position drift or wider accuracy circles on the display. Keeping the cell above 3.6V under load prevents the receiver from entering reduced-sensitivity mode.

fēnix 2 shuts off without warning before the battery indicator hits zero

After a battery swap, the fuel gauge algorithm in the fēnix 2 needs a full charge-discharge cycle to recalibrate its voltage-to-capacity map. Until that cycle completes, the device can cut power abruptly when the cell hits the low-voltage cutoff threshold — even while the indicator still shows one or two bars. Run the watch from a full charge until it shuts off naturally, then charge it to 100% without interruption. After that single cycle the indicator will align with actual remaining capacity.