O2 XDA Xphone SV10B Replacement Battery 3.7V 950mAh

O2 XDA Xphone — 3.7V Li-ion Replacement Battery (SV10B)

This is a 3.7V lithium-ion replacement battery for the O2 XDA Xphone. It carries 950mAh (3.52Wh) capacity and slots into the original battery bay using the stock connector. The XDA Xphone is a mid-2000s Windows Mobile PDA phone, and original cells at this age are routinely below 40% of rated capacity.

• XDA Xphone fit: The XDA Xphone runs a single-cell 3.7V nominal rail. This cell matches that rail, the physical footprint, and the contact polarity. Both OEM part numbers SV10B and SV16A share the same bay dimensions and connector pin layout on this handset.
• Bench tested on actual hardware: We cycled this cell through charge and load on the bench. The BMS held charge termination at the correct 4.2V ceiling and tripped the low-voltage cutoff cleanly before the cell dropped into damage territory.
• Fuel gauge recalibration after swap: After fitting this cell, run one full uninterrupted discharge to the auto-shutoff point, then charge to 100% without interruption. The XDA Xphone's fuel gauge IC reads the old cell's impedance curve until it completes that first full cycle against the new cell.

Sudden shutdown at 20–30% on the XDA Xphone after a cell swap

The XDA Xphone's power management reads a voltage curve mapped to the original aged cell. A new cell has a steeper voltage cliff in the lower charge band — under modem transmit or screen load, voltage sags below the cutoff threshold while the gauge still reads 20–30%. The phone shuts down not because the cell is empty, but because the fuel gauge IC hasn't learned the new cell's discharge curve. One complete discharge-charge cycle resets the coulomb counter reference and resolves this.

Device won't power on after sitting in storage with a flat battery

If the XDA Xphone has been stored with a depleted cell, the replacement battery may also arrive at a low resting voltage. When cell voltage drops below approximately 2.5V, the BMS enters lockout mode and blocks current flow to protect the cell. The phone won't respond to the power button and may show no charge indicator. Connect to a wall charger — not a PC USB port — and leave it for 15–20 minutes before attempting to power on. The charge IC on the handset needs a sustained trickle to bring the cell voltage above the BMS re-enable threshold of around 3.0V.