About this replacement
Samsung Gear 1 SM-V700 — 3.7V Li-Polymer Replacement Battery (B030FE)
This 3.7V, 250mAh Li-Polymer cell replaces the original B030FE battery in the Samsung Gear 1 smartwatch (SM-V700). It restores power to the watch's fitness tracking, notification, and timekeeping functions. Dimensions are 30.60 × 21.00 × 4.80mm — confirm these against your existing cell before ordering.
- Gear 1 / SM-V700 platform fit: The Gear 1 and SM-V700 share the same chassis, connector orientation, and B030FE cell spec. Voltage rail, tab spacing, and BMS handshake are identical across both model designations — one cell covers both.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the SM-V700. The BMS accepted the new cell without fault codes, the fuel gauge initialised correctly after a full charge cycle, and the watch resumed all sensor functions normally.
- Post-swap charging requirement: After fitting this cell, place the watch on its magnetic charger immediately and charge it to 100% before wearing it. The Gear 1's fuel gauge IC loses its reference point when the original cell is removed — it cannot recalibrate the battery level accurately without one complete charge cycle from near-zero on the new cell.
Why the Gear 1 drains to flat in one day after a battery swap
The Gear 1 runs an always-on display alongside continuous heart rate sampling — both draw current even when the watch face is idle. A new cell with an uncalibrated fuel gauge IC will also misreport state-of-charge, which can trigger unexpected shutdowns well before the cell is actually empty. The fix is a full charge cycle to 100% immediately after fitting the replacement, which lets the IC set accurate high and low reference points. After that first full cycle, multi-day battery life should return to normal Gear 1 levels.
Gear 1 not pairing to the phone after battery replacement
Removing the cell cuts power to the BLE controller entirely, which wipes the active pairing session stored in volatile memory. When the watch restarts on the new battery, it comes up as an unpaired device — your phone still holds the old session record, so the two can't re-establish the link automatically. Go into your phone's Bluetooth settings, forget the Gear 1 entry, then open the Samsung Gear app and run a fresh pair. The watch will appear as a new device and pair cleanly.