Samsung Galaxy S8 Plus EB-BG955ABE Replacement Battery 3.85V

Samsung Galaxy S8 Plus — 3.85V Li-Polymer Replacement Battery (EB-BG955ABE)

This 3.85V, 3500mAh Li-Polymer battery replaces the original EB-BG955ABE cell in the Samsung Galaxy S8 Plus. It fits the Galaxy S8 Plus, Galaxy S8 Plus TD-LTE, Dream 2, and SM-G955F among other listed variants. Capacity figures come from the product data — 13.48Wh at rated voltage.

• S8 Plus variant compatibility: The SM-G955 lineup shares a common battery bay geometry, connector pinout, and BMS handshake protocol across regional variants including TD-LTE and Dream 2. One cell design covers all listed models because Samsung locked the same power rail and NTC thermistor arrangement across the series.
• Bench tested on actual hardware: We ran this cell on an SM-G955F through charge initiation, fast-charge handshake, and thermal monitoring. The BMS accepted charge current without fault flags, and the NTC thermistor reported within spec throughout the cycle.
• Fuel gauge recalibration on first use: On first use after installation, disable fast charging and run one full discharge-to-charge cycle. This lets the fuel gauge IC map the new cell's discharge curve before the charge IC pushes high current into an uncalibrated cell — skipping this step is the leading cause of erratic percentage readings after a swap.

Sudden shutdown at 20–30% on the S8 Plus after a cell swap

The S8 Plus uses a coulomb counter combined with a voltage-based lookup table stored in the fuel gauge IC. When a new cell goes in, that table is still calibrated to the old cell's internal resistance profile. Under high-current loads — active LTE, Bluetooth, and a bright display simultaneously — the new cell's voltage can dip below the shutdown threshold even while the gauge still reads 20–30%. The fix is one complete uninterrupted discharge from 100% to automatic power-off, followed by a full charge without interruption. After that cycle, the fuel gauge IC resets its reference points against the actual cell curve and the premature shutdowns stop.

USB-PD fast charge not activating on the first cycle after replacement

Samsung's Adaptive Fast Charging protocol requires a BMS handshake before the charge IC ramps current above the standard 5V/1A baseline. On a freshly installed cell, the BMS sometimes withholds that handshake until it has completed one baseline charge cycle and confirmed cell integrity. This is not a fault — it is a protection state. Charge the phone once at standard speed using the original Samsung charger, allow it to reach 100%, then unplug and replug. On the second connection, the fast-charge handshake completes and the charger steps up to 9V/1.67A as normal.