MyPhone MP-S-L 8920 Replacement Battery 3.7V 1000mAh

MyPhone 8920 Series — 3.7V Li-ion Replacement Battery (MP-S-L)

This is a 3.7V, 1000mAh Li-ion cell that replaces part number MP-S-L in the MyPhone 8920, 8920 Mark, 8920TV Mark Pro, and 9005 handsets. It slots into the same battery bay and connects to the same charging IC as the original. Capacity is 1000mAh — match that to your original label before ordering.

• 8920 series compatibility: The 8920, 8920 Mark, and 8920TV Mark Pro share the same 3.7V battery bay, connector pitch, and BMS handshake — that is why one cell covers all three. The 9005 uses the same form factor. Swap without modification.
• Bench tested on actual hardware: We cycled this cell through a full discharge and charge sequence on the MyPhone 8920 platform. The BMS accepted charge on the first cycle, and the protection circuit tripped correctly at the low-voltage cutoff threshold — no anomalies recorded.
• Fuel gauge recalibration on first use: On first use after installation, disable fast charging and run one full discharge-charge cycle at standard rate. This lets the fuel gauge IC build an accurate discharge curve against the new cell before the charge IC starts pushing higher current into an uncalibrated cell.

Why the MyPhone 8920 reports wrong battery percentage after a cell swap

The fuel gauge IC on the 8920 stores a learned discharge curve from the old cell. When a new cell goes in, that stored curve no longer matches the actual voltage-versus-capacity profile of the replacement. The result is a percentage readout that drifts — often reading higher than real charge, then jumping downward. One complete discharge to 3.0V followed by a full charge at standard rate resets the coulomb counter and lets the IC map the new cell correctly.

Sudden shutdown at 20–30% on the replacement cell

This happens when the modem or screen draws a current spike the cell cannot sustain at that state of charge — voltage drops below the BMS cutoff threshold and the phone shuts down before the gauge reads zero. It is most common in the first few cycles when the cell has not yet reached full capacity. Run two or three complete charge-discharge cycles to let the cell condition. If shutdowns persist past cycle three, check the battery contacts on the board for oxidation and clean with isopropyl alcohol before reseating.