Grundig MPixx 8000 Replacement Battery 3.7V 1050mAh

Grundig MPixx 8000 Series — 3.7V Li-Polymer Replacement Battery (YK503450PL 1S1P)

This 3.7V 1050mAh lithium-polymer cell replaces the original battery in the Grundig MPixx 8000, MPixx 8400, and MPixx 8800 portable media players. The YK503450PL 1S1P matches the physical footprint at 51.80 × 32.85 × 5.40mm and the connector pinout of the factory cell. Capacity is 1050mAh (3.89Wh), identical to the OEM specification.

• MPixx 8000, 8400, and 8800 compatibility: All three models share the same single-cell 3.7V battery bay, connector orientation, and BMS handshake logic, so one cell fits the entire range without modification.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on an MPixx 8000 unit. The BMS accepted the cell without fault codes, and the protection circuit tripped correctly at the low-voltage cutoff threshold.
• First charge after installation: Connect the player to its charger immediately after fitting the new cell and leave it for a full uninterrupted charge before first use. Media players frequently enter a deep-discharge protection state when a fresh cell is installed at resting voltage, and a continuous charge cycle clears this state before normal use begins.

Battery percentage jumping after cell swap on the MPixx series

The MPixx firmware reads battery state through a voltage-threshold lookup table stored in firmware, not a coulomb counter. After fitting a new cell, the player has no reference data for the new cell's discharge curve, so the percentage indicator recalibrates over the first few charge cycles. Expect erratic jumps — typically between 20% and 80% — for the first two or three full cycles. Run the player from a full charge down to automatic shutdown, then recharge fully, and the indicator stabilises. By cycle three, readings should track within roughly 10% of actual remaining capacity.

Playback cuts out before the battery indicator reaches empty

The audio amplifier inside the MPixx draws a brief current spike to drive headphone output, particularly at higher volume levels. Near the end of a cell's discharge curve, battery voltage sags under this load and can dip below the BMS protection cutoff — even when the indicator still shows charge remaining. The device shuts down to protect the cell, not because the indicator is accurate. To push past this, reduce playback volume in the final 15–20% of charge; lower amplifier draw reduces the voltage sag and delays the cutoff trip. If the issue appears early in the cell's life, check that the terminal voltage under load stays above 3.0V.