Nokia 2.4 WT242 Replacement Battery 3.85V 4400mAh

Nokia 2.4 / TA-1277 / TA-1275 — 3.85V Li-Polymer Replacement Battery (WT242)

This is a 3.85V, 4400mAh lithium-polymer replacement battery for the Nokia 2.4 smartphone, covering variants TA-1277, TA-1275, and TA-1274. It replaces the original WT242 cell when the phone no longer holds a charge or shuts down unexpectedly. The battery measures 85.90 × 64.85 × 4.42mm and is a direct fit for the Nokia 2.4 chassis.

• Nokia 2.4 variant coverage: The TA-1274, TA-1275, and TA-1277 share the same battery bay dimensions, connector pinout, and BMS handshake protocol — all three accept the WT242 cell without modification.
• Bench tested on actual hardware: We cycled this battery through full charge and discharge on a Nokia 2.4 unit. The BMS accepted charge normally, protection circuits triggered correctly at low-voltage threshold, and the fuel gauge IC tracked state-of-charge without error flags after one complete cycle.
• Fuel gauge recalibration on first use: After installation, disable fast charging and run one full discharge-to-charge cycle before resuming normal use. This allows the fuel gauge IC to map its coulomb counter against the new cell's actual discharge curve — skipping this step often causes percentage jumps or early shutdowns on the first few cycles.

Why the Nokia 2.4 reports wrong battery percentage after a cell swap

The Nokia 2.4 uses a coulomb-counter fuel gauge IC that builds its charge model from the previous cell's impedance and discharge curve. When you install a new cell, that stored model no longer matches the actual battery, so the reported percentage drifts from real capacity. The gauge recalibrates itself over one or two full discharge-charge cycles. Until that happens, readings of 100% that drop suddenly to 60%, or an OS that shows 30% remaining and then powers off, are expected — not a fault with the replacement cell.

Sudden shutdown at 20–30% on the replacement cell

This is a voltage-cliff failure: under peak modem load or a screen-on burst, the cell's output voltage drops faster than the fuel gauge expects, hitting the low-voltage cutoff before the reported percentage reaches zero. It happens most often when the fuel gauge IC is still calibrated to the worn-out cell's flatter discharge curve. Run two full discharge-charge cycles without fast charging — this resets the IC's internal model to match the new cell. After recalibration, shutdowns at 20–30% should stop; if they persist past three full cycles, verify the replacement cell resting voltage reads at least 3.85V with a multimeter before reinstallation.