Philips GoGear HDD6330 Replacement Battery Q25-C3 3.7V 680mAh

Philips GoGear HDD6330 30GB — 3.7V Li-ion Replacement Battery (Q25-C3)

This 3.7V, 680mAh Li-ion cell replaces the original battery in the Philips GoGear HDD6330 30GB portable media player. It matches the OEM part numbers Q25-C3 and GZM-1A and fits the hard drive-based DAP released in the mid-2000s. If the original cell no longer holds charge or the player refuses to power on, this is the direct replacement.

• GoGear HDD6330 30GB fitment: The HDD6330 runs a single-cell 3.7V Li-ion pack on a compact PCB with a low-current BMS sized for audio and HDD spin-up draw. This cell matches those electrical tolerances and the physical footprint at 51.78 × 35.82 × 4.74mm.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the HDD6330 platform and confirmed the BMS accepted full charge current without triggering protection cutoff. Voltage held stable across the HDD spin-up event at boot.
• Post-install charge cycle on the HDD6330: After fitting a new cell, connect the GoGear to its original charger before pressing power. The HDD6330's protection circuit can lock out the power button when cell voltage is below threshold — the charger bypasses this and trickle-charges the cell back into the normal operating window.

Battery percentage jumping after cell swap on the HDD6330

The GoGear HDD6330 estimates charge state using voltage thresholds stored against the old cell's discharge curve. A new cell has a slightly different resting voltage profile, so the indicator reads the new cell as fuller or emptier than it actually is. This settles after two to three full charge and discharge cycles as the firmware recalibrates. Do not trust the percentage display in the first few days — let the player discharge until it shuts off naturally, then charge to full before using the reading as a guide.

Playback cutting out before the battery indicator shows empty

As a Li-ion cell approaches the bottom of its discharge curve, output voltage sags. The HDD6330's audio amplifier pulls enough current during playback that this sag briefly drops voltage below the minimum the amplifier needs, causing the player to cut audio or restart. The hard drive also draws a current spike during track changes, which compounds the sag at low charge states. If this happens consistently, stop playback around 10–15% shown charge and connect the charger — the cell voltage at that point is near 3.5V and further discharge risks a deep-discharge lock.