Dopod HD mini Replacement Battery BB92100 3.7V 1100mAh

Dopod HD mini / T5555 — 3.7V Li-ion Replacement Battery (BB92100)

This is a 3.7V, 1100mAh Li-ion replacement battery for the Dopod HD mini, T5555, A6380, and G9. It replaces OEM part numbers BB92100, 35H00137-00M, and BA S430. If your original cell no longer holds adequate charge through a normal day of use, this is the direct swap.

• HD mini / T5555 / A6380 / G9 compatibility: These four models share the same battery bay dimensions, connector pinout, and BMS communication protocol, which is why one cell covers all of them. The 45.66 × 41.78 × 6.20mm footprint matches the factory cavity without modification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on compatible hardware. The BMS accepted charge correctly, voltage regulation held stable across the discharge curve, and no unexpected cutoff events occurred under normal screen and modem load.
• Fuel gauge recalibration on first use: After fitting this cell, run one complete discharge down to automatic shutdown, then charge uninterrupted to 100% before using the device normally. The Windows Mobile fuel gauge IC is calibrated to the old cell's discharge curve — skipping this cycle causes the percentage counter to read inaccurately from the start.

Why the HD mini reports wrong battery percentage after a cell swap

Windows Mobile devices store the battery's discharge curve in the fuel gauge IC, and that data is tied to the old cell's characteristics. When a new cell goes in, the IC keeps using the old curve, so its percentage estimates drift immediately. The counter may show 80% when the real state of charge is closer to 50%, or drop suddenly when the curve deviates. One full discharge-to-shutdown followed by a complete uninterrupted charge resets the coulomb counter against the new cell's actual behaviour.

Sudden shutdown at 20–30% remaining on the replacement cell

This is a voltage cliff issue, not a capacity issue. Under combined screen and modem load, the cell's terminal voltage drops faster than the fuel gauge predicts, hitting the BMS low-voltage cutoff while the display still shows charge remaining. It is most common before the fuel gauge IC completes its first full recalibration cycle. Run one full discharge-to-shutdown and charge cycle — after that, the cutoff point and the percentage display align more closely. If shutdowns continue past the second cycle, check that the cell is seated fully and the connector contacts are clean.