DEASY T258 Nokia N95 Replacement Battery 3.7V 1000mAh

DEASY Nokia N95 / T258 Series — 3.7V Li-ion Replacement Battery

This is a 3.7V, 1000mAh Li-ion cell for the Nokia N95 and compatible models including T258, TL1266, TS518, and TS808. It restores power to devices where the original cell has degraded, swollen, or stopped holding a charge. Capacity and voltage match the original Nokia N95 battery specification.

• N95 platform compatibility: The T258, TL1266, TS518, and TS808 share the same 3.7V single-cell architecture and physical footprint — 53.00 × 33.90 × 5.70mm — so one cell fits across all listed variants without connector or housing modification.
• Bench tested on actual hardware: We ran this cell through full charge and discharge cycles on the N95 platform. The BMS responded correctly to the phone's charge IC, accepted standard charge current without tripping cutoff, and held voltage above the shutdown threshold through the discharge curve.
• Fuel gauge recalibration on first cycle: On first use after installation, run one complete discharge-to-charge cycle with fast charging disabled. This lets the fuel gauge IC map the new cell's discharge curve before reporting percentage — skipping this step causes erratic percentage jumps in the first few days of use.

Why the Nokia N95 reports wrong battery percentage after a cell swap

The N95 uses a fuel gauge IC that builds a discharge model from the cell it first charged. When you swap in a new cell, that model still references the old cell's impedance and capacity curve. The percentage reading drifts — sometimes showing 50% when the cell is nearly flat. One full discharge-to-shutdown followed by a complete charge resets the coulomb counter and recalibrates the IC to the new cell. After that cycle, percentage accuracy returns to normal.

Sudden shutdown at 20–30% on the replacement cell

This happens when the cell voltage drops below the load threshold before the fuel gauge registers empty — common on freshly installed cells that haven't been calibrated. Under GSM modem or screen load, the N95 pulls current spikes that cause brief voltage sag; if the cell reads 3.5V at rest but sags below 3.2V under load, the phone cuts out. It's not a faulty cell — it's an uncalibrated gauge reading resting voltage, not loaded voltage. Complete one full discharge cycle down to automatic shutdown, then charge uninterrupted to 100%, and the cutoff threshold will align correctly.