Archos AV605 120GB Compatible Battery 3.7V 5200mAh

Archos AV605 120GB & AV605 WiFi 120GB — 3.7V Li-Polymer Replacement Battery

This is a 3.7V, 5200mAh Li-Polymer replacement battery for the Archos AV605 120GB and AV605 WiFi 120GB portable media players. It slots directly into the battery bay and connects to the same onboard charging circuit the original cell used. Capacity is rated at 19.24Wh — matching the original specification.

• AV605 and AV605 WiFi compatibility: Both models share the same battery footprint, connector pinout, and 3.7V charging rail. The WiFi variant draws more current when the wireless module is active, but the battery itself is identical across both units.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the AV605 platform. The onboard BMS accepted charge current without fault, and the protection circuit tripped correctly at the low-voltage threshold — no runaway, no false cutoffs at mid-charge.
• First charge after install: AV605 units that have sat unused often enter a deep discharge protection state. Connect the charger immediately after fitting the new cell and leave it for at least 30 minutes before attempting to power on — the device needs a slow trickle before it accepts normal charge current.

Battery percentage jumping after cell swap on the AV605

The AV605 estimates charge level by reading cell voltage against a fixed lookup table stored in firmware. A new cell with a slightly different discharge curve will read as a different percentage than the actual state of charge — especially in the middle of the range. This recalibrates over two to three full charge and discharge cycles. Run the player down to auto-shutdown, then charge fully to 4.2V each time, and the indicator will settle.

Playback cutting out before the battery indicator shows empty

The audio amplifier in the AV605 needs a stable voltage above roughly 3.4V to drive output without dropout. As the cell approaches the end of its discharge curve, voltage sags under load faster than the display circuit alone would cause. The firmware reads voltage at idle and may still show one bar of charge, but the amplifier circuit loses headroom and cuts the audio signal. If playback stops while the indicator shows charge remaining, charge the unit — the cell is closer to depletion than the indicator suggests.