Qtek 9100 Replacement Battery 3.7V 2350mAh WIZA16

Qtek 9100 — 3.7V Li-ion Replacement Battery (WIZA16)

This is a 3.7V, 2350mAh Li-ion replacement battery for the Qtek 9100 Windows Mobile PDA phone. It replaces OEM part numbers WIZA16, 35H00062-00M, and HTC098347. Capacity is rated at 8.7Wh and the cell fits within the original 52.12 x 38.08 x 12.38mm battery bay.

• Qtek 9100 fit: The 9100 shares its battery platform with early HTC Windows Mobile hardware. The connector, cell geometry, and BMS contact layout match the original bay — no modification needed for installation.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the 9100 platform. The BMS handshake completed correctly, charge termination triggered at the expected cutoff voltage, and no fault flags were logged during the test cycle.
• Fuel gauge recalibration on first use: After fitting this cell, run one complete discharge to shutdown followed by a full uninterrupted charge before relying on the percentage readout. The 9100's fuel gauge IC was calibrated against the old cell's discharge curve — it needs one full cycle to map the new cell accurately.

Why the Qtek 9100 reports wrong battery percentage after a cell swap

The 9100 uses a coulomb-counting fuel gauge IC that builds its capacity model from previous charge and discharge data. When you swap the cell, the IC still references the old discharge curve. This causes the percentage display to read either higher or lower than actual state of charge. One full discharge-to-shutdown followed by a full charge resets the learning baseline and brings the readout back into alignment with the new cell's actual capacity.

Sudden shutdown at 20–30% remaining on the Qtek 9100

This happens when the fuel gauge IC hasn't yet recalibrated and the cell voltage drops below the protection threshold under load before the displayed percentage reflects it. The 9100's modem and display draw current spikes that cause a voltage sag on a newly installed cell — the BMS cuts power to protect the cell even though the gauge still shows charge remaining. Run one full calibration cycle first. If shutdowns continue after that, check that the cell contacts are fully seated, as a high-contact-resistance connection amplifies voltage sag under load and triggers cutoff earlier than expected.