About this replacement
Ticwatch WE11056 / 2 Series — 3.8V Li-Polymer Replacement Battery (SP372728SE)
This is a 3.8V, 300mAh lithium-polymer cell for the Ticwatch Fit (WE11056) and the Ticwatch 2, 2E, and 2S. It replaces the original SP372728SE cell when capacity has faded after repeated charge cycles. The cell measures 27.60 × 26.30 × 3.30mm and connects via the original ribbon flex connector.
- WE11056, 2, 2E, and 2S compatibility: These four models share the same mainboard footprint and flex connector pinout, so one cell fits all. The BMS on each variant handles the same 3.8V nominal rail with a 4.35V charge ceiling — no rewiring or adapter needed.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on the WE11056 platform. The BMS accepted the cell immediately, voltage settled at 3.80V under load, and the fuel gauge IC registered capacity without a manual reset.
- Post-swap charge requirement: After fitting this cell, place the watch on its charger straight away and charge to 100% before using it. The fuel gauge IC on this platform cannot calibrate its zero-to-full reference without a complete charge cycle from near-zero immediately after a cell swap — skipping this causes persistent incorrect battery percentage readings.
Why the Ticwatch 2 Series drains a new cell faster in the first week
A freshly fitted cell has a slightly different internal impedance than a worn original. The watch's health-monitoring sensors — particularly the optical heart rate module — draw current against that new impedance profile, which can read as higher consumption for several days. The fuel gauge IC also recalibrates during this period, which can make the battery percentage jump or drop unexpectedly. This is normal. After three to five full charge cycles, drain rate stabilises to expected multi-day use.
Watch not pairing with phone after battery swap
Removing the battery clears the active BLE session between the watch and your phone. The phone's Bluetooth stack still holds an old pairing record that no longer matches the watch's re-initialised state. Go to your phone's Bluetooth settings, forget the Ticwatch device entirely, then re-pair from scratch through the Mobvoi app. The watch should appear in the scan list within 30 seconds of powering on with the new cell fitted.