Samsung SCH-F609 Replacement Battery PPM63M5H 3.7V 650mAh

Samsung SCH-F609 — 3.7V Li-ion Replacement Battery (PPM63M5H)

This is a 3.7V, 650mAh Li-ion replacement battery for the Samsung SCH-F609 mobile phone. It slots directly into the SCH-F609 battery bay and restores power to calls, messaging, and standard phone functions. Voltage and capacity match the OEM PPM63M5H specification.

• SCH-F609 fit: The SCH-F609 uses a low-capacity single-cell Li-ion pack with a fixed 3.7V nominal rail. This replacement carries the same PPM63M5H form factor and contact pin layout, so the phone's charge IC and protection circuit board recognise the cell without modification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on a compatible test rig. The BMS held cutoff correctly at both ends of the voltage window — no false full-charge flag and no premature low-voltage trip under simulated call load.
• Fuel gauge recalibration on first use: On first install, disable any fast-charge mode and run one complete discharge-to-charge cycle at standard current. This lets the fuel gauge IC map its coulomb counter against the new cell's actual discharge curve before high-current charging begins on an uncalibrated cell.

Why the SCH-F609 reports wrong battery percentage after a cell swap

The SCH-F609's fuel gauge IC builds its percentage estimate from a discharge curve stored in memory — a curve calibrated against the old cell. When a new cell goes in, that stored curve no longer matches actual cell behaviour. The gauge reports inaccurate numbers until it sees a full discharge and charge cycle with the new cell. Run the phone down to auto-shutdown, then charge uninterrupted to 100% and the gauge will re-anchor its reference points. After one full cycle, percentage readings stabilise.

Sudden shutdown at 15–25% on the replacement cell

This happens when the cell voltage drops sharply under modem or backlight load — a voltage cliff the fuel gauge did not predict. The phone's protection circuit reads voltage below the safe floor and cuts power before the displayed percentage reaches zero. It is not a faulty battery; it is the gauge misreading state-of-charge on an uncalibrated cell. Charge the phone to 100%, confirm the charger reads a full charge, then repeat the single full-discharge calibration cycle described above.