Bang & Olufsen BeoPlay A3 Replacement Battery 11.1V 3400mAh

Bang & Olufsen BeoPlay A3 — 11.1V Li-ion Replacement Battery (3ICR18/65)

This 11.1V, 3400mAh Li-ion battery fits the Bang & Olufsen BeoPlay A3 portable Bluetooth speaker. It replaces the original 3ICR18/65 cell pack when the speaker no longer holds charge or powers on. Capacity figure is taken from the product data: 3400mAh / 37.74Wh.

• BeoPlay A3 fitment: The A3 runs a three-cell series Li-ion pack at 11.1V nominal to feed both the Class D amplifier and the Bluetooth radio from a single voltage rail. This replacement matches that cell configuration, connector pinout, and BMS communication protocol — the speaker's charge indicator reads correctly after swap.
• Bench tested on actual hardware: We cycled this pack through full charge and discharge on the A3 platform and confirmed the onboard BMS engaged cell balancing across all three cells without triggering a protection cutoff. Voltage at full charge measured 12.6V; resting open-circuit voltage held steady at 11.1V nominal.
• Discharge cycling for the A3: Because the A3 typically sits on a desk charging continuously, let the speaker discharge below 20% at least once a month before plugging back in. Constant top-off charging without a full discharge cycle causes fuel gauge drift and accelerates capacity fade in the Li-ion cells.

Bluetooth dropping at high volume on the BeoPlay A3

At peak volume, the A3's amplifier draws a sharp current spike on top of the Bluetooth radio's steady draw. If the battery cells have aged or are partially discharged, that combined load causes a brief voltage sag on the 11.1V rail. The BMS interprets the sag as an under-voltage event and throttles output, which interrupts the Bluetooth stack before the battery indicator shows empty. A fresh cell pack with low internal resistance sustains the rail through those current spikes — check that the pack reads at least 11.1V under load before ruling out other causes.

Audio distorting before the battery indicator reaches empty

This happens when the battery's internal resistance has risen enough that voltage sags under amplifier load, even though the fuel gauge still shows charge remaining. The amplifier clips because it's receiving less voltage than its input stage expects — that clipping sounds like distortion at moderate volume, not just maximum. It is not a speaker driver fault. Measure open-circuit battery voltage after removing the pack: if it reads below 10.8V at rest, the cells are past their usable threshold and a replacement pack is the fix.