Amazfit Pace Replacement Battery 3.8V 290mAh PL372427V

Amazfit Pace / A1612 / A1602 — 3.8V Li-Polymer Replacement Battery (PL372427V)

This 3.8V, 290mAh lithium-polymer cell replaces the original battery in the Amazfit Pace smartwatch, covering model numbers A1612 and A1602. It powers the display, optical heart rate sensor, GPS module, and BLE stack. Dimensions are 28.60 × 23.70 × 3.70mm — confirm your existing cell matches before ordering.

• Pace / A1612 / A1602 platform fit: All three model numbers share the same PCB layout, connector pinout, and BMS handshake requirements. The fuel gauge IC on this platform expects a 3.8V nominal cell — substituting a 3.7V cell causes false low-battery shutdowns at partial charge.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the Pace platform. The BMS accepted the cell without fault flags, and the fuel gauge re-calibrated correctly after a full charge-to-cutoff cycle post-swap.
• Post-swap charge protocol for Pace: 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 Pace loses its reference voltage when the old cell is disconnected — without a full charge cycle from near-zero, it will report inaccurate percentages for days.

Why the Pace battery reads 0% right after a cell swap

The Pace uses a coulomb-counting fuel gauge IC that tracks charge state relative to a stored reference. When the old cell is removed, that reference is wiped. The IC has no data to work from, so it defaults to 0% or shuts the watch down entirely. This is not a fault with the new cell. Charge the watch to 100% uninterrupted on the magnetic charger — the IC resets its baseline at the top of the charge curve and reads normally from that point forward.

Pace not pairing to the phone after battery replacement

Removing the battery cuts power to the BLE controller mid-session, which drops the active pairing key stored in the watch. The phone still holds its end of the bond, but the watch no longer recognises it. Go into your phone's Bluetooth settings, forget the Amazfit Pace device entirely, then re-open the Zepp or Amazfit app and pair from scratch. Do not attempt to pair before the watch has completed its first full charge cycle after the swap.