About this replacement
Beats Powerbeats 2 / Powerbeats 3 — 3.7V Li-Polymer Replacement Battery (CPP-566)
This is a 3.7V, 90mAh Li-Polymer cell that replaces the CPP-566 battery inside one earbud of the Beats Powerbeats 2 and Powerbeats 3 wireless earphones. It fits the compact housing of either earbud pod and restores power to the Bluetooth audio and call circuits. Use the capacity figure from the original cell — 90mAh — to confirm you have the right part before opening the housing.
- Powerbeats 2 and 3 compatibility: Both generations use the same CPP-566 cell form factor, voltage rail, and connector footprint. The BMS on each earbud circuit recognises the cell by voltage window, not a digital handshake, so a direct swap works across both model lines.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on a Powerbeats 2 earbud. The BMS accepted the new cell without error, held a stable voltage plateau through audio and Bluetooth radio draw, and cut off cleanly at the low-voltage threshold.
- Powerbeats earbud reassembly tip: The ribbon connector on the CPP-566 is orientation-sensitive — flipping it 180 degrees will seat it physically but will break the circuit. Confirm the gold contacts face the correct direction before closing the housing or you will get no power at all.
Why a Powerbeats earbud cuts out mid-call on a freshly replaced cell
The earbud draws current from two sources at once during a call — the Bluetooth radio and the audio amplifier circuit. On a new cell that has not completed its first full charge cycle, the resting voltage can sit slightly below the earbud's operational floor. When both loads spike simultaneously, the BMS reads a voltage dip and trips the protection circuit. This is not a faulty cell. Charge the earbud fully before making your first call, and the cutout behaviour stops after the cell reaches its rated capacity window.
Earbud shows full charge in the app but dies within minutes of use
This symptom points to a cell delivered at storage voltage — typically around 3.6V — which the charging circuit interprets as nearly full and terminates the charge early. The state-of-charge reading in the Beats app mirrors what the earbud's BMS reports, not the true cell capacity. Put the earbud on charge for a full uninterrupted cycle, then drain it through normal use before charging again. After two to three full cycles the BMS recalibrates its state-of-charge tracking and the reported level matches actual capacity.