iRiver P7 Replacement Battery 3.7V 2000mAh Li-Polymer PG822401AA

iRiver P7 — 3.7V Li-Polymer Replacement Battery (PG822401AA)

This is a 3.7V 2000mAh Li-Polymer replacement battery for the iRiver P7 portable media player. It fits the P7, 1P0716SIL 16GB, 1P0708SIL 8GB, and REI-P7(B) variants. The OEM part number is PG822401AA.

• P7 platform compatibility: The 1P0716SIL, 1P0708SIL, and REI-P7(B) all share the same 3.7V Li-Polymer cell format, connector pinout, and BMS voltage thresholds as the base P7. One battery fits the entire line.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge on the P7 platform. The BMS accepted charge current without fault codes, and the protection circuit engaged cleanly at the low-voltage cutoff.
• Post-install charge cycle: After fitting this battery, connect the P7 to a charger and let it charge fully before first use. Media players commonly enter a deep-discharge protection state after sitting unused, and the device may not respond to the power button until the cell clears that threshold via slow trickle charge.

Battery percentage jumping after cell swap on the P7

The P7 uses a voltage-threshold method to estimate battery level — it does not use a coulomb counter. After fitting a new cell, the firmware's voltage-to-percentage map is calibrated against the old, degraded cell's discharge curve. This mismatch causes the indicator to jump or read inaccurately for the first few cycles. Run two to three full charge and discharge cycles, and the readings will stabilise as the firmware re-anchors its thresholds to the new cell's actual resting voltage.

Playback cutting out before the battery indicator shows empty

The P7's audio amplifier draws a spike of current during playback that the battery indicator's voltage sampling does not capture between refresh intervals. As the cell nears the bottom of its discharge curve, this current draw causes a brief voltage sag that crosses the BMS cutoff threshold before the displayed percentage reaches zero. The BMS then shuts down the device to protect the cell. This is expected behaviour, not a fault — it becomes less pronounced after the first few full cycles when the firmware's low-voltage reference stabilises around 3.0V.