iRiver E10 Replacement Battery 3.7V 720mAh Li-Polymer

iRiver E10 / E10CT Series — 3.7V Li-Polymer Replacement Battery

This 3.7V 720mAh Li-Polymer cell replaces the original battery in the iRiver E10, E10CT, HDD Jukebox, and IRI-E10 portable media players. Capacity matches the factory spec at 720mAh (2.66Wh). If your E10 won't hold a charge or dies unexpectedly during playback, this is the swap to make.

• E10 and E10CT compatibility: These models share the same battery bay dimensions and 3.7V power rail. The connector pinout and cell footprint — 48.93 × 30.26 × 4.70mm — are identical across the E10 lineup, so one part number covers all variants listed.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on E10 hardware. The BMS accepted the cell without fault flags, charge current stepped down correctly at top-of-charge, and the protection circuit tripped cleanly at low-voltage cutoff.
• First charge after a cell swap: After installing this battery, plug the E10 into its charger before powering it on. A freshly installed Li-Polymer cell can sit at a voltage low enough to trigger the device's deep discharge protection state. Let it trickle charge for 30 minutes first so the device accepts a normal charge current.

Battery percentage jumping around after installing a new cell

The E10 tracks battery level by reading cell voltage against a fixed lookup table calibrated to the original cell's discharge curve. A new cell with slightly different internal resistance will produce voltage readings that don't match those reference points. The indicator recalibrates itself over two to three full charge-discharge cycles. Run the player down to auto-shutoff, then charge fully to 4.2V each time until the percentage display stabilises.

Playback cutting out before the battery indicator shows empty

The audio amplifier inside the E10 draws a short burst of higher current when driving headphones at volume, especially with bass-heavy tracks. At the tail end of a cell's discharge curve — typically below 3.5V — the cell can't sustain that burst without a momentary voltage sag. The player's protection circuit reads that sag as an undervoltage event and cuts out, even if the indicator still shows charge remaining. If this happens consistently, the cell is near end-of-life and the replacement cycle is due.