Samsung AB503442CE SGH-D908 Replacement Battery 3.7V 700mAh

Samsung SGH-D908 / SGH-D900 Series — 3.7V Li-ion Replacement Battery (AB503442CE)

This is a 3.7V Li-ion cell rated at 700mAh (2.59Wh), sized to fit the Samsung SGH-D900, SGH-D900i, SGH-D908, and SGH-E788, among others. It replaces OEM part numbers AB503442CE, AB503442CC, AB503442AE, and several regional variants. The cell matches the original footprint at 42.75 × 36.55 × 4.38mm — no case modification needed.

• SGH-D900 family compatibility: The D900, D900i, D908, and E788 all share the same battery bay dimensions, connector pinout, and 3.7V nominal rail. One cell covers the full group because Samsung standardised the BMS handshake and connector orientation across these mid-2000s flip models.
• Bench tested on actual hardware: We ran this cell through a full charge-discharge cycle on a D900 unit. The BMS accepted the charge without tripping, temperature stayed within normal limits, and the protection circuit cut cleanly at both the low-voltage floor and the 4.2V ceiling.
• Fuel gauge recalibration on first cycle: After fitting this cell, disable any fast-charge accessory for the first complete discharge-to-charge cycle. The phone's fuel gauge IC was calibrated to the old cell's discharge curve — one full cycle at standard current lets it relearn the new curve before you push higher charge rates into an uncalibrated cell.

Why the SGH-D908 reports wrong battery percentage after a cell swap

The D908 uses a coulomb-counting fuel gauge IC that tracks charge by integrating current over time. That counter was trained against the original cell's capacity and internal resistance. A new cell has a different impedance profile, so the IC's percentage estimate drifts almost immediately. The fix is straightforward: run one full discharge down to auto-off, then charge uninterrupted to 100% — the IC resets its reference points against the new cell. After that single cycle, percentage readouts stabilise.

Sudden shutdown at 20–30% on a replacement cell

This happens when the phone's CPU, modem radio, and display fire simultaneously, pulling a short burst of current the cell struggles to sustain at mid-charge. A Li-ion cell's internal resistance is higher when it is new and not yet broken in, so voltage sags sharply under that load spike. The phone's low-voltage cutoff reads the sag as a dead cell and shuts down — even though the state-of-charge estimate still shows 20–30%. After two or three full charge cycles, internal resistance drops and the sag narrows. If shutdowns persist beyond three cycles, check resting voltage after a full charge — it should read 4.18–4.20V with no load.