Samsung SGH-i550w AB47350BE Replacement Battery 3.7V 800mAh

Samsung SGH-i550w — 3.7V Li-ion Replacement Battery (AB47350BE)

This is a 3.7V Li-ion cell rated at 800mAh (2.96Wh), replacing OEM part AB47350BE in the Samsung SGH-i550w. It fits the original battery slot and connects to the same contact rails. Voltage, capacity, and connector match the factory specification.

• SGH-i550w fit: The i550w runs a single-cell 3.7V Li-ion architecture with a three-pad contact strip. This cell matches that voltage rail and contact layout. The BMS on the phone expects a cell in that nominal range — swapping to a mismatched voltage causes the charge IC to reject the cell outright.
• Bench tested on actual hardware: We cycled this cell through a full charge and load discharge sequence, confirming BMS handshake, cutoff at the correct low-voltage threshold, and charge termination at 4.2V. No premature cutoff or thermal event was observed.
• Fuel gauge recalibration on first use: After fitting this cell, run one complete discharge down to auto-shutdown, then charge uninterrupted to 100%. The SGH-i550w's fuel gauge IC is calibrated to the old cell's discharge curve — without one full cycle, the percentage readout will drift or stall at mid-charge.

Sudden shutdown at 20–30% on the SGH-i550w after a cell swap

This happens because the fuel gauge IC still holds the discharge curve of the original degraded cell. When the new cell hits a voltage region the old model didn't map accurately, the IC thinks the cell is exhausted and triggers shutdown. The phone's modem and screen create brief high-current draws that accelerate the voltage drop at that threshold. Run one full discharge-to-shutdown and a complete recharge — the coulomb counter resets against the actual cell behaviour and the false cutoff disappears.

Phone won't power on after the replacement cell sat discharged in storage

Li-ion cells self-discharge over time, and if the AB47350BE sat below approximately 2.5V, the BMS enters a lockout state to prevent cell damage. The SGH-i550w will show nothing on screen — no charging animation, no boot. Connect the phone to a wall charger, not a USB port, and leave it for 20–30 minutes without pressing the power button. Once the cell climbs back above the BMS recovery threshold, the charging indicator will appear and normal operation resumes.