DEASY T258 Nokia N95 N96 Replacement Battery 3.7V 750mAh

DEASY T258 / TL1266 / TS518 / TS808 — 3.7V Li-ion Replacement Battery

This is a 3.7V 750mAh Li-ion cell for Nokia smartphones running on the T258, TL1266, TS518, and TS808 battery platform — including the Nokia N95 and N96. It restores power to phones where the original cell no longer holds voltage under load. Capacity is 750mAh (2.78Wh), sourced direct from the product data.

• Multi-model fit — T258 platform: The T258, TL1266, TS518, and TS808 share identical footprint dimensions (53.00 × 33.90 × 5.70mm), the same 3.7V single-cell architecture, and a common connector pinout. The Nokia N95 and N96 use this cell family, which is why one replacement covers all of them.
• Bench tested on actual hardware: We cycled this cell through full charge and load discharge on the N95 platform. The BMS held cutoff cleanly at the low-voltage threshold and accepted charge current without triggering protection lockout on first contact with the charge IC.
• Fuel gauge recalibration on first cycle: After installing this cell, disable any fast-charge accessories and run one complete discharge-to-charge cycle before normal use. The phone's fuel gauge IC was calibrated to the old cell's discharge curve — one full cycle lets it recalibrate against the new cell before it starts reporting accurate percentages.

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

Nokia's fuel gauge IC tracks charge state using a coulomb counter trained on the original cell's impedance and discharge curve. A new cell has different characteristics, so the counter starts out of sync. The phone may show 100% immediately after a short charge, then drop suddenly. One full discharge below 5% followed by an uninterrupted charge to 100% resets the counter baseline. After that cycle, percentage readings stabilise.

Sudden shutdown at 20–30% remaining on the replacement cell

This happens when the modem radio or display fires a high-current draw and the cell voltage drops sharply — the protection circuit reads an undervoltage event and cuts output before the fuel gauge has caught up. It is not a faulty cell; it is the fuel gauge IC reading a stale discharge model. Run the recalibration cycle described above. If shutdowns persist after two full cycles, check that the battery connector contacts are fully seated — a partial connection raises effective impedance and worsens voltage sag under load.