Acer Liquid S110 Compatible Battery BT.00103.002 3.7V 1400mAh

Acer Liquid S110 — 3.7V Li-ion Replacement Battery (BT.00103.002)

This is a 3.7V 1400mAh Li-ion cell for the Acer Liquid S110, Stream, NeoTouch S110, and S110 smartphones. It replaces OEM part BT.00103.002 and 1UF504553-1-T0582. Install it when the original cell no longer holds voltage under screen or modem load.

• Liquid S110 and NeoTouch S110 compatibility: These models share the same battery bay dimensions and connector pinout. The 57.44 × 50.32 × 5.05mm cell fits each variant without modification, and the BMS communication lines map to the same fuel gauge IC across all listed models.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the Liquid S110 platform. The BMS accepted the cell on first connection, charge termination triggered correctly at 4.2V, and the protection circuit tripped as expected under an over-discharge load test.
• Fuel gauge recalibration on first use: After installation, disable fast charging and run one full discharge-to-charge cycle before resuming normal use. The Liquid S110's fuel gauge IC needs this cycle to map the new cell's discharge curve — skipping it causes the percentage readout to drift or drop suddenly under modem load.

Sudden shutdown at 20–30% on the Liquid S110 after a cell swap

The Liquid S110 uses a coulomb-counter fuel gauge that was calibrated against the original cell's discharge curve. A new cell has a slightly different voltage-to-capacity profile, so the gauge misreads remaining charge. When the display shows 25%, the actual cell voltage may already be at the knee of the discharge curve — around 3.5V. Under the current spike from LTE radio or a bright screen, voltage sags below the BMS cutoff threshold and the phone shuts off. One full uninterrupted discharge to automatic power-off, followed by a full charge, resets the calibration.

Phone won't power on after sitting in storage for several months

Li-ion cells left uncharged for extended periods self-discharge below the BMS re-enable threshold — typically 2.5V per cell. At that voltage, the protection circuit locks out to prevent further discharge, and the phone appears completely dead. Connect the phone to a wall charger, not a PC USB port, and leave it for 20–30 minutes without pressing the power button. The charge IC will trickle current into the cell until the BMS re-enables at approximately 3.0V, after which normal charging resumes.