About this replacement
Beats Solo 2.0 / Solo 3.0 — 3.7V Li-Polymer Replacement Battery (AEC353535)
This 3.7V, 350mAh lithium-polymer cell replaces the internal battery in the Beats Solo 2.0 and Solo 3.0 wireless headphones (model A1796). It powers both the audio drivers and the Bluetooth radio. Fit this cell when the original battery no longer holds a usable charge.
- Solo 2.0 and Solo 3.0 compatibility: Both models share the same battery cavity dimensions, voltage rail, and connector pinout. The AEC353535 cell measures 33.94 × 34.88 × 3.64mm — matching the original footprint so the cell seats correctly without modification.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on a Solo 3.0 unit. The BMS accepted the new cell on first connection, voltage held steady across combined Bluetooth and audio load, and the charging circuit reached full termination without fault flags.
- First-cycle charging on Solo headphones: After fitting the replacement cell, run a full charge via the original charging cable before using the headphones. The Solo's fuel gauge calibrates against a completed charge cycle — skipping this step produces an inaccurate battery indicator until at least one full cycle is logged.
Why the Solo 3.0 cuts out mid-track on a new battery
The Solo 3.0 runs two loads off the same cell: the audio amp and the Bluetooth radio. When the cell ships at storage voltage (around 3.6–3.7V), sudden combined draw can trip the BMS undervoltage threshold even though the indicator shows adequate charge. The cutout is a protection event, not a faulty cell. Charge the battery fully before first use — once the cell sits at 4.2V, the headphones handle the combined load without tripping protection.
Battery indicator stuck at full after replacement
The Solo's onboard fuel gauge tracks capacity by coulomb counting from a known reference point. Swapping the cell resets that reference, so the gauge reads incorrectly until it sees one complete charge-to-discharge cycle. The indicator will show full — or drop suddenly — until the first full cycle is logged. Charge to 100% via cable, use the headphones until the low battery alert sounds, then recharge fully. After that cycle the indicator tracks accurately.