Artfone CF241A Replacement Battery 3.7V 900mAh

Artfone CF241A / CS181 / CS181A — 3.7V Li-ion Replacement Battery

This is a 3.7V, 900mAh (3.33Wh) Li-ion cell that replaces the original battery in the Artfone CF241A, CS181, and CS181A. All three models share the same battery bay dimensions (53.00 × 34.00 × 4.80mm) and voltage rail. Fit the cell, close the cover, and the phone powers on normally.

• CF241A, CS181, and CS181A compatibility: These three Artfone models run the same 3.7V single-cell architecture with an identical connector pinout and physical footprint. The BMS on each device accepts this cell without configuration changes.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the CF241A platform. The charge IC accepted the cell on the first cycle, BMS protection tripped correctly at low-voltage cutoff, and the fuel gauge IC began tracking state-of-charge without error flags.
• Fuel gauge recalibration on first use: After fitting this cell, disable any fast-charge mode and run one complete discharge-to-charge cycle before normal use. The fuel gauge IC on these Artfone models calibrates its discharge curve against the first full cycle — skipping this step leaves the coulomb counter reading against the old cell's curve.

Why the CF241A reports wrong battery percentage after a cell swap

The fuel gauge IC on the CF241A stores a learned discharge curve from the original cell. When a new cell goes in, that stored curve no longer matches the actual voltage-to-capacity relationship of the replacement. The phone reads voltage, maps it to the old curve, and displays an inaccurate percentage. One full discharge-charge cycle overwrites the stored curve and realigns the coulomb counter to the new cell's behaviour.

Sudden shutdown at 20–30% on the replacement cell

This happens when the fuel gauge IC still references a degraded cell's voltage curve. As load increases — screen backlight, network polling — the new cell's voltage drops briefly below the threshold the phone expects at that reported percentage. The system interprets this as a critical low-voltage event and shuts down. Run one complete calibration cycle first. If shutdowns persist after calibration, check that the display percentage stabilises above 3.6V under moderate load.