About this replacement
LG Music Flow P5 Series — 3.7V Li-ion Replacement Battery (EAC63100301)
This 3.7V, 1800mAh Li-ion cell replaces the original battery in the LG Music Flow P5 and Music Flow P5 Strap portable Bluetooth speakers. It also fits the NP5558MC and NP5550B variants. When the original cell degrades, the speaker loses cordless operation — this battery restores it.
- Music Flow P5 and P5 Strap compatibility: These two models share the same battery bay dimensions, connector pinout, and BMS handshake protocol. The 68.60 × 38.00 × 6.40mm cell fits the physical bay without modification, and the protection circuit communicates with the speaker's charge controller correctly.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on the P5 platform and confirmed the BMS triggered protection cutoff at the correct low-voltage threshold. The charge controller accepted the pack without faults or error indicators.
- Fuel gauge calibration after install: After fitting this battery, run the speaker down until it shuts off automatically, then charge it uninterrupted to 100% before using it again. Skipping this step causes the fuel gauge to report inaccurate charge levels from the first cycle.
Capacity fade from constant top-off charging on the P5
The P5 is typically used as a desk or shelf speaker, which means most owners plug it in whenever it drops below 80%. Shallow cycling — never letting the cell discharge below 50% — causes fuel gauge drift over time and accelerates capacity loss in the Li-ion cell. The battery's coulomb counter loses accuracy when it never sees a full charge-discharge cycle. Discharge the speaker below 20% at least once a month before recharging to prevent this.
Audio distorting before the battery indicator reaches empty
At high volume, the amplifier draws a sharp current spike that momentarily drags cell voltage below the clean-power threshold — even when the indicator still shows charge remaining. The speaker's audio circuit clips under this voltage sag, producing distortion that sounds like speaker damage but clears immediately at lower volume. A degraded or deeply cycled cell sags harder under the same load. If distortion appears consistently at high volume, check resting cell voltage — a healthy cell should read above 3.6V at rest.