Acer S120 Replacement Battery 3.7V 1500mAh BT.0010S.001

Acer S120 / Liquid Metal — 3.7V Li-ion Replacement Battery (BT.0010S.001)

This is a 3.7V, 1500mAh Li-ion cell for the Acer S120 and Liquid Metal smartphones. It replaces OEM part BT.0010S.001 (also cross-referenced as BAT-510 and ICP494261SRU 1S1P). Fit the replacement when the original cell no longer holds a usable charge through a normal day.

• S120 and Liquid Metal compatibility: Both phones share the same 66 × 42 × 5mm cell footprint, identical 3.7V voltage rail, and the same BMS connector pinout — so one cell fits both without modification.
• Bench tested on actual hardware: We ran this cell through full charge and load cycles on the S120 platform. The BMS accepted the cell on first insertion, charge current ramped correctly through CC/CV stages, and the protection circuit tripped cleanly at the expected over-discharge threshold.
• Fuel gauge recalibration on first use: After installing this cell, disable fast charging for one complete discharge-charge cycle. The fuel gauge IC on the S120 was calibrated to the original cell's discharge curve. Giving it one slow cycle at standard current lets the coulomb counter reset its reference points before any high-current charging pushes into an uncalibrated state.

Why the Acer S120 reports wrong battery percentage after a cell swap

The S120 uses a fuel gauge IC that tracks charge state by counting coulombs against a stored discharge curve from the factory cell. When you fit a new cell, that stored curve no longer matches what's physically in the phone. The gauge reads the open-circuit voltage, maps it to the old curve, and outputs an incorrect percentage. Run one full discharge down to auto-shutdown, then charge uninterrupted to 100% without using the phone. After that cycle, the gauge re-anchors its endpoints and percentage accuracy returns.

Sudden shutdown at 20–30% on the replacement cell

This happens when the cell voltage drops below the modem or display load threshold before the fuel gauge registers low battery. Under peak current draw — LTE radio, screen at full brightness — a freshly installed cell with an uncalibrated gauge can reach the BMS cutoff voltage while the OS still shows 25% remaining. The BMS cuts power to protect the cell, and the phone shuts off without warning. Completing one full calibration cycle as described above shifts the gauge's low-end endpoint to match the new cell's actual voltage cliff, typically around 3.4–3.5V under load.