Bang & Olufsen BeoPlay P6 Replacement Battery 7.4V 2600mAh

Bang & Olufsen BeoPlay P6 — 7.4V Li-ion Replacement Battery (C129D1)

This is a 7.4V, 2600mAh Li-ion battery for the Bang & Olufsen BeoPlay P6 portable Bluetooth speaker. It replaces OEM part C129D1 (also cross-referenced as 2INR19/66). Fit models include BeoPlay P6, 11400, and 1140026.

• BeoPlay P6 compatibility: The P6, 11400, and 1140026 all run on the same 7.4V cell platform with identical connector orientation and BMS communication. Swapping to this battery requires no wiring changes — the fuel gauge handshake initialises on first charge.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on a P6 unit. The BMS accepted the pack without fault flags, cell balancing kicked in correctly at top-of-charge, and the protection circuit tripped cleanly at the low-voltage cutoff threshold.
• Monthly discharge cycle for the P6: The P6 typically sits on a desk or shelf and gets topped off constantly. Let the speaker drain below 20% at least once a month before recharging — this prevents fuel gauge drift and slows capacity fade on the Li-ion cell caused by continuous shallow cycling.

Audio distorting before the battery indicator reaches empty on the P6

When a Li-ion cell ages, internal resistance rises. Under the combined current draw of the amplifier and Bluetooth radio at moderate-to-high volume, terminal voltage sags below what the amplifier rail needs — even if the reported charge level still shows 20–30%. The amplifier clips because it can't pull enough clean voltage, and you hear distortion before the speaker shuts off. A fresh cell with lower internal resistance holds terminal voltage stable under the same load. After fitting this battery, run it through one full discharge before judging audio quality at volume.

P6 won't wake from USB-C after sitting unused for several weeks

A deeply discharged Li-ion cell can drop below the minimum acceptance voltage for USB-C Power Delivery negotiation — the charger and speaker fail to handshake, so charging never starts and the speaker appears dead. This is not a fault with the port or the charger. Connect the P6 to a standard 5V USB-A source first, which bypasses PD negotiation and trickle-charges the cell back above ~2.5V per cell. Once the pack recovers to that threshold, switch to the USB-C charger and complete a full charge cycle.