Sony SRS-X7 Replacement Battery 7.4V 2600mAh LIS2181HNPD

Sony SRS-X7 / SRS-BTX300 — 7.4V Li-ion Replacement Battery (LIS2181HNPD)

This is a 7.4V, 2600mAh Li-ion replacement battery for the Sony SRS-X7 and SRS-BTX300 portable Bluetooth speakers. It replaces OEM part LIS2181HNPD and slots into the same battery compartment as the original. Fit this when the original cell no longer holds charge or the speaker shuts off unexpectedly during playback.

• SRS-X7 and SRS-BTX300 compatibility: Both speakers share the same 7.4V two-cell Li-ion architecture, battery connector pinout, and BMS communication protocol — that is why one part number covers both. Swapping a mismatched voltage pack into either model triggers an immediate BMS lockout.
• Bench tested on actual hardware: We cycled this pack through charge and discharge on the SRS-X7 chassis. The BMS handshake completed correctly on first insertion, the charging circuit accepted the cell without error flags, and the fuel gauge reported accurate state-of-charge across the full voltage window from 8.4V down to 6.0V cutoff.
• Monthly discharge cycle for SRS-X7 users: If the speaker sits on a desk and gets topped off constantly before dropping below 50%, let it run down below 20% at least once a month before recharging. Continuous shallow cycling causes fuel gauge drift on the SRS-X7's battery management circuit and accelerates capacity fade in the Li-ion cells.

Audio distortion before the battery indicator reaches empty on the SRS-X7

As cell voltage drops toward the lower end of the discharge curve, the SRS-X7's internal amplifier loses headroom before the battery indicator triggers a low-battery warning. The result is audible clipping or distortion at moderate-to-high volume while the speaker still shows one or two bars remaining. This is a voltage sag issue — the amp draws a current spike on transients that the aging cell cannot sustain cleanly. A fresh 7.4V cell with intact internal resistance resolves this; if distortion starts above 7.0V on the discharge curve, the original cell has degraded beyond useful capacity.

Speaker wakes from USB but won't power on from the battery after sitting unused for weeks

Li-ion cells self-discharge at roughly 1–3% per month under normal storage, but a cell already weakened by age can drop below the SRS-X7 BMS minimum acceptance threshold — approximately 5.5V — during extended storage. When the cell sits below that threshold, the BMS blocks the discharge path entirely as a protection measure, and the power button produces no response. Connect the speaker to USB power for at least 30 minutes before pressing the power button; this allows the charger to trickle the cell back above the BMS re-initialisation threshold of around 6.0V before the speaker attempts to draw load current.