Philips GoGear HDD1630 Replacement Battery 3.7V 700mAh

Philips GoGear HDD1630 / HDD070 Series — 3.7V Li-ion Replacement Battery (31042005223)

This 3.7V 700mAh Li-ion cell replaces the original battery in the Philips GoGear HDD1630 6GB and HDD070 2GB portable media players. It matches the OEM part number 31042005223 and fits the physical bay without modification. Capacity is 700mAh (2.59Wh), identical to the factory spec.

• GoGear HDD1630 and HDD070 platform fit: These models share the same 3.7V single-cell configuration, connector pinout, and battery bay dimensions — 45.87 × 21.08 × 8.75mm. The BMS on each device reads voltage and temperature from the same contact layout, so one cell covers the full compatibility list.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the HDD070 platform. The BMS accepted the cell without fault flags, charge termination triggered correctly at 4.2V, and the protection circuit tripped as expected at the low-voltage cutoff threshold.
• First charge after install: The GoGear HDD series enters a deep discharge protection state during long storage. After fitting the new cell, connect the charger and leave it for at least 30 minutes before attempting to power on — the device needs a slow trickle to exit protection mode before it will accept normal charge current.

Playback cutting out before the battery indicator shows empty

The HDD1630 runs a small hard drive alongside its audio amplifier. When the cell voltage sags under combined load near the end of discharge, the amplifier loses enough headroom to cut out — even though the fuel gauge still shows a bar or two remaining. This happens because the voltage-threshold indicator was calibrated to the old, degraded cell. After a few full charge and discharge cycles on the new cell, the gauge recalibrates and cutout behaviour normalises. If it persists, check that charge termination is reaching 4.2V at the battery contacts.

Battery percentage jumping erratically after cell swap

The GoGear's fuel gauge estimates charge state by tracking voltage thresholds set against the original cell's discharge curve. A new cell holds a flatter discharge curve than a degraded one, so the gauge misreads the state of charge and jumps — often from 80% to 20% with no warning. This is not a fault with the cell. Run two to three full charge-discharge cycles and the gauge will remap its thresholds to the new cell's curve. Confirm the cycle is complete when the charger terminates at 4.2V and the device powers off cleanly at the low-voltage cutoff.