Samsung YH-820 Replacement Battery 3.7V 750mAh PPSB

Samsung YEEP YH-820 — 3.7V Li-ion Replacement Battery (PPSB)

This is a 3.7V 750mAh Li-ion battery for the Samsung YEEP YH-820 series of portable media players. It fits the YH-820, YH-820S, YH-820MW, and YH-820MW/XSH among other variants. Install it when the original cell no longer holds a charge or the player shuts off unexpectedly during playback.

• YH-820 series compatibility: All variants in this lineup run the same 3.7V single-cell configuration with an identical connector footprint and BMS handshake protocol. The battery communicates charge state to the firmware using voltage thresholds — a mismatched cell triggers false low-battery shutdowns.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the YH-820 platform. The BMS accepted the cell without fault codes, and charge termination triggered correctly at 4.2V as expected for a standard Li-ion cell.
• Post-swap charging on the YH-820: After installing a new cell, connect to the charger before attempting to power on. A freshly installed battery sitting at storage voltage — around 3.6–3.8V — may cause the firmware to read an incomplete charge state and refuse to boot until the charge controller initialises the cell properly.

Battery percentage jumping after cell swap on the YH-820

After replacing the battery, the on-screen percentage indicator often reads erratically — jumping from 80% to 20% and back within minutes. The YH-820 firmware estimates charge state by reading cell voltage against a fixed lookup table calibrated to the original aged cell. A new cell has a flatter discharge curve at full capacity, which the firmware misreads as irregular charge swings. Run two or three full charge and discharge cycles, and the percentage display will stabilise as the firmware recalibrates its voltage-to-capacity mapping.

Playback cutting out before the battery indicator shows empty

The audio amplifier in the YH-820 draws a spike of current at higher volume levels, pulling the cell voltage briefly below the BMS protection threshold even when the displayed charge appears sufficient. This is voltage sag — the internal resistance of the cell under load causes a momentary dip that triggers shutdown. It becomes more pronounced as a cell ages, but can also appear briefly on a new cell at very high volume. Reduce playback volume and verify the cell voltage reads above 3.5V under load using the device's diagnostics if accessible.