MWG XDA 35H10008-80 Replacement Battery 3.7V 1700mAh

MWG XDA — 3.7V Li-Polymer Replacement Battery (35H10008-80)

This 3.7V, 1700mAh lithium-polymer cell replaces the original battery in the MWG XDA Windows Mobile smartphone. It fits the OEM battery slot directly and matches the original 35H10008-80 specification. Capacity is 6.29Wh — sourced to match the factory cell dimensions of 94.33 × 50.53 × 3.49mm.

• XDA platform fit: The XDA uses a single-cell Li-Polymer pack with a three-contact connector carrying voltage, ground, and a thermistor line for charge control. This cell matches that connector pinout and the physical envelope, so the battery door closes flush without modification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the XDA platform and confirmed the BMS handshake completes correctly — the device accepted charge current without fault flags and did not trigger a premature cutoff on the first cycle.
• Fuel gauge recalibration on first use: After fitting this cell, run one full discharge to the automatic shutdown point, then charge uninterrupted to 100% before normal use. The XDA's fuel gauge IC is calibrated against a discharge curve — skipping this step leaves the coulomb counter misaligned with the new cell and causes erratic percentage readings.

Why the XDA reports wrong battery percentage after a cell swap

The XDA uses a fuel gauge IC that builds its percentage estimate from a stored discharge curve — not a live voltage reading alone. When the old, degraded cell is removed, that stored curve no longer matches the new cell's characteristics. The IC starts counting from a mismatched baseline, so 60% on screen may correspond to a cell already near its low-voltage cutoff. One complete discharge-charge cycle resets the coulomb counter and realigns the gauge to the replacement cell's actual capacity.

Sudden shutdown at 20–30% on the replacement cell

This happens when the fuel gauge IC has not yet recalibrated and the reported percentage is higher than the cell's actual remaining charge. Under modem or display load, the XDA draws enough current to pull cell voltage below the 3.0V BMS cutoff threshold — triggering an immediate shutdown despite a non-zero percentage on screen. The fix is a full calibration cycle: drain the phone to automatic shutdown, then charge to 100% in a single uninterrupted session. After that cycle, the fuel gauge tracks the new cell accurately and the early shutdowns stop.