Nokia N95 GT03B Replacement Battery 3.7V 1000mAh

BANNO GT03B — 3.7V Li-ion Replacement Battery

This is a 3.7V, 1000mAh Li-ion cell that replaces the original battery in the Nokia N95 and N95 8GB. It fits directly into the same battery bay, using the same three-contact connector. Capacity is 1000mAh (3.7Wh), matching the original specification.

• Nokia N95 and N95 8GB compatibility: Both handsets share the same battery bay dimensions, contact layout, and BMS handshake protocol — that is why one cell covers both variants. The physical footprint is 53.00 × 33.90 × 5.70mm, matching the original cavity without modification.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on an N95 unit. The BMS accepted the cell on first connection, charge termination triggered correctly at 4.2V, and the fuel gauge IC registered the cell without throwing a battery error code.
• Fuel gauge recalibration on first use: After installing this cell, run one complete discharge down to automatic shutdown, then charge uninterrupted to 100% before normal use. The N95's fuel gauge IC calibrates its coulomb counter against that first full cycle — skipping it causes the percentage reading to drift or jump in the first few days.

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

The N95 uses a fuel gauge IC that builds a discharge curve model over time. When the original cell ages, that model drifts to match the old cell's degraded behaviour. A new cell has a different internal resistance and a steeper voltage-capacity curve at the bottom end, so the IC maps percentage incorrectly until it relearns. One full discharge-to-shutdown followed by a complete charge resets the coulomb counter reference point. After that cycle, percentage readings stabilise.

Sudden shutdown at 20–30% on a freshly installed cell

This happens when the fuel gauge IC still holds the old cell's cutoff voltage model. The N95's processor and WCDMA modem draw a combined current spike during calls or data sessions that the IC's stale model interprets as a low-voltage event, triggering shutdown even though the cell still has charge remaining. It is not a fault in the cell — it is a calibration mismatch. Perform one full discharge cycle to let the IC reset its low-voltage threshold to the new cell's actual 3.0V cutoff floor.