About this replacement
Samsung Galaxy Ace 2 / GT-I8160 — 3.7V Li-ion Replacement Battery (EB425161LU)
This is a 3.7V, 1200mAh Li-ion cell for the Samsung Galaxy Ace 2 and its regional variants, including the GT-I8160, GT-I8160P, and GT-S7562. It replaces OEM part numbers EB425161LU and EB425161LA. The cell fits the standard removable battery bay and connects via the original three-contact connector.
- GT-I8160 and GT-S7562 platform compatibility: Both handsets share the same battery bay dimensions, contact pitch, and BMS handshake protocol. The 60.40 × 50.30 × 4.20mm cell footprint seats flush in both chassis without modification.
- Bench tested on actual hardware: We ran this cell on a GT-I8160 unit and monitored BMS communication through a full charge cycle. Charge acceptance was normal from the first cycle, and the protection circuit tripped correctly at low-voltage cutoff.
- Fuel gauge recalibration on first use: After installing a new cell, disable any adaptive battery or power-saving features and run one full discharge-to-charge cycle. The fuel gauge IC on the Ace 2 builds its discharge curve model from the first cycle — skipping this leaves the coulomb counter working off the old cell's data.
Why the Ace 2 reports wrong battery percentage after a cell swap
The Ace 2 uses a coulomb-counting fuel gauge IC that stores a discharge curve calibrated to the original cell's impedance and capacity profile. When a new cell goes in, that stored curve no longer matches the physical cell. The percentage reading the OS displays is calculated against old data, so the number drifts. One complete discharge from 100% to automatic shutdown, followed by a full charge, resets the reference point and brings the reported figure back in line with actual charge state.
Sudden shutdown at 20–30% on the replacement cell
This happens when the fuel gauge IC has not yet mapped the new cell's voltage cliff — the point where cell voltage drops sharply under load from the modem or display. The OS sees 25% remaining, but the cell voltage collapses below the BMS cutoff threshold the moment current draw spikes, triggering an immediate shutdown. The fix is the same full discharge-charge cycle: once the IC has recorded the actual voltage drop curve for this cell, it adjusts the shutdown prediction and stops cutting out early. After calibration, the phone should reach automatic low-battery shutdown at or below 3.4V.