About this replacement
LG PK3 Portable Speaker — 3.7V Li-Polymer Replacement Battery (EAC63918501)
This 3.7V, 5200mAh Li-Polymer battery replaces the original EAC63918501 cell inside the LG PK3, PK3-N, and PK3-N.ABRALLK portable Bluetooth speakers. It fits the exact footprint at 97.00 × 28.50 × 16.00mm and connects directly to the speaker's charge management board. Replace this battery when the original no longer holds a charge or the speaker fails to power on.
- PK3 and PK3-N compatibility: All three listed variants — PK3, PK3-N, and PK3-N.ABRALLK — share the same battery bay dimensions, connector pinout, and charge IC. One cell fits all three without modification.
- Bench tested on actual hardware: We cycled this cell through the PK3's charge board and confirmed the protection circuit communicates correctly with the onboard BMS — charge termination and over-discharge cutoff both triggered at expected thresholds.
- Monthly discharge cycle for the PK3: The PK3 is typically left on a desk and topped off constantly. Let the battery discharge below 20% at least once a month before plugging in — constant shallow charging without a full discharge causes fuel gauge drift and accelerates capacity fade on the Li-Polymer cell.
Audio distorting before the battery indicator reaches empty on the PK3
As a Li-Polymer cell ages, its internal resistance rises. Under the combined current draw of the amplifier and Bluetooth radio, voltage sags faster than the fuel gauge can track. The amplifier hits its minimum supply voltage before the indicator shows low battery, causing clipping and distortion. A new cell at full 5200mAh capacity restores the voltage headroom the amplifier needs at high output.
PK3 not waking from USB-C after sitting unused for several weeks
Li-Polymer cells self-discharge during storage. If the PK3 sits unused long enough, the cell can drop below the minimum voltage the USB-C PD negotiation requires to begin a charge session — typically around 2.5V. The charge IC sees a cell voltage too low to accept standard input and refuses to start. Connect the speaker to a 5V USB-A charger instead of USB-C, which bypasses PD negotiation and trickle-charges the cell back above 3.0V before normal charging resumes.