Nokia BLN-3 9110 Communicator Replacement Battery 3.7V 1150mAh

Nokia 9110 / 9110i Communicator — 3.7V Li-ion Replacement Battery (BLN-3)

This is a 3.7V Li-ion replacement cell rated at 1150mAh (4.26Wh), built to fit the Nokia 9110 and 9110i Communicator. The Communicator's combined phone and PDA load draws from a single cell, so a degraded original battery hits hard across all functions — calls, messaging, and data. This swap restores that capacity to factory spec.

• 9110 and 9110i compatibility: Both models share the same battery bay geometry, contact pin layout, and 3.7V supply rail. The BLN-3 part number covers both variants — no adapter, no wiring change required.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the 9110 platform. The BMS accepted the handshake without fault codes, and the charge IC reached termination voltage correctly without overrun.
• Fuel gauge recalibration on first use: After fitting this cell, run one full discharge down to automatic shutdown, then charge uninterrupted to 100% before normal use. The 9110's fuel gauge IC was calibrated to the original cell's discharge curve — skipping this step leaves the percentage readout unreliable from the start.

Sudden shutdown at 20–30% on the Nokia 9110 after a cell swap

The 9110 Communicator runs a combined GSM modem and PDA processor off the same cell. During active calls or data sync, the modem's transmit burst pulls current spikes that a partially discharged cell cannot sustain at voltage. When cell voltage drops below roughly 3.2V under that load, the BMS cuts output before the fuel gauge ever reaches 0%. The fix is a full calibration cycle — discharge to auto-shutoff, then a full uninterrupted charge — so the fuel gauge maps the new cell's actual voltage cliff rather than the old one.

Battery percentage jumping or freezing after installing a new BLN-3

The 9110's fuel gauge IC stores a charge model based on the previous cell's coulomb count and internal resistance. A new cell has a different impedance profile, so the old model mismaps capacity — you'll see the percentage freeze at a number, jump several points at once, or read full charge when the cell is part-drained. This is not a fault in the replacement cell. One complete discharge-to-shutoff followed by a full charge forces the IC to rewrite its reference curve against the new cell. After that cycle, percentage readout stabilises.