O2 XDA Orbit 2 POLA160 Replacement Battery 3.7V 1350mAh

O2 XDA Orbit 2 — 3.7V Li-ion Replacement Battery (POLA160)

This 3.7V, 1350mAh Li-ion cell replaces the original battery in the O2 XDA Orbit 2 and XDA Orbit II. The XDA Orbit 2 is a Windows Mobile PDA phone — its battery powers the processor, display, GSM radio, and GPS simultaneously. Match the OEM part number POLA160 or 35H00101-00M before ordering to confirm fit.

• XDA Orbit 2 and Orbit II compatibility: Both model names refer to the same hardware platform. They share the same battery bay dimensions, connector pinout, and BMS handshake protocol — this cell fits both without modification.
• Bench tested on actual hardware: We ran this cell through full charge and discharge cycles on the XDA Orbit 2 platform. The BMS communicated correctly with the device charge IC, and protection circuits triggered at expected voltage thresholds under combined GSM and display load.
• Fuel gauge recalibration on first use: After fitting this cell, run one complete discharge to shutdown followed by an uninterrupted full charge before relying on the battery percentage indicator. The Windows Mobile fuel gauge IC carries calibration data from the old cell — one full cycle resets it against the new cell's discharge curve.

Sudden shutdown at 20–30% on the XDA Orbit 2

The XDA Orbit 2 draws peak current when the GSM radio transmits or the GPS acquires a fix. An aged cell cannot hold its voltage rail under that spike, and the BMS cuts power before the fuel gauge reads zero. This is a voltage cliff — the cell's internal resistance has risen to the point where load current collapses the terminal voltage below the BMS cutoff threshold. A new cell with lower internal resistance sustains the voltage rail through those peaks. After fitting this replacement, run a full recalibration cycle so the fuel gauge IC maps the new cell's actual capacity curve.

Device will not power on after sitting in storage

Li-ion cells self-discharge in storage. If the XDA Orbit 2 has been unused for months, the cell voltage may have dropped below 2.5V per cell — the threshold where the BMS enters lockout to prevent damage. The device will show no response when the power button is pressed. Connect the charger and leave it for 20–30 minutes without attempting to power on — the charge IC will trickle current into the cell until voltage recovers above the BMS re-enable threshold, typically around 3.0V, at which point normal charging resumes.