About this replacement
Amazfit POP / Bip U (A2009, A2017) — 3.85V Li-Polymer Replacement Battery (PL382222GH)
This is a 3.85V, 225mAh Li-Polymer cell sized at 22.60 × 21.50 × 3.80mm, matching the original PL382222GH specification. It fits the Amazfit POP, Bip U, A2009, and A2017 smartwatches. Replace it when the original cell no longer holds charge through a full day of normal use.
- POP and Bip U platform fit: Both models share the same chassis dimensions, connector pinout, and fuel gauge IC — so one cell covers the full A2009/A2017 lineup without modification.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on a Bip U unit. The fuel gauge IC registered the new cell correctly after a full charge from near-zero, and the BMS held the 4.35V charge ceiling without tripping.
- Post-swap charge requirement: After fitting this cell, place the watch on its charger immediately and charge to 100% before first use. The fuel gauge IC on these Amazfit platforms loses its reference point when the cell is swapped — it cannot recalibrate until it sees a complete charge cycle from near-zero.
Why the Amazfit POP fuel gauge reads incorrectly after a cell swap
The POP and Bip U use a coulomb-counting fuel gauge IC that tracks charge state relative to a stored reference. Removing the old cell clears that reference entirely. Until the new cell completes one full charge cycle from near-zero to 100%, the IC has no baseline, so percentage readings will jump or read 0% even on a charged cell. This is not a fault with the replacement cell — it resolves after the first complete charge.
Watch not pairing to phone after battery replacement
Pulling the battery during a swap ends the active BLE session between the watch and the Zepp app. The phone retains the old pairing record, but the watch has no matching session on boot. Go to Bluetooth settings on your phone, forget the Amazfit device, then re-pair fresh through the Zepp app. Do this after the watch has completed its first full charge to 100%.