JBL Flip AEC653055-2S Replacement Battery 7.4V 1050mAh

JBL Flip / Flip 1 — 7.4V Li-Polymer Replacement Battery (AEC653055-2S)

This is a 7.4V, 1050mAh Li-Polymer replacement battery for the JBL Flip and Flip 1 portable Bluetooth speaker. It fits both generations of the original Flip — the compact cylindrical speaker released before the Flip 2. OEM part number AEC653055-2S matches the physical footprint and connector on both units.

• Flip and Flip 1 compatibility: Both units share the same internal battery bay dimensions and use the same two-cell Li-Polymer pack wired to a common BMS connector. The 55.40 × 29.30 × 12.96mm cell fits the cavity without modification.
• Bench tested on actual hardware: We ran this pack through charge and discharge cycles on a Flip unit. The BMS accepted charge immediately from the micro-USB port, balanced both cells, and triggered low-voltage cutoff cleanly without tripping the speaker's fault state.
• Fuel gauge reset after swap: After fitting a new pack, discharge the speaker fully until it powers off on its own, then charge uninterrupted to 100% before normal use. Skipping this step leaves the onboard fuel gauge reading from an incorrect baseline, causing the LED indicator to report inaccurate charge levels.

Why the Flip shows full charge but audio cuts out mid-session

A Li-Polymer cell kept constantly topped off between 80–100% without full discharge cycles develops fuel gauge drift — the pack reports more usable capacity than it can actually deliver. When the amplifier draws peak current during louder passages, the degraded cell can't sustain the voltage rail, and the BMS shuts down the output to protect the cells. The speaker reads "full" right up until it drops. One full discharge-to-cutoff cycle followed by an uninterrupted charge resets the fuel gauge and restores accurate reporting.

Audio distorting before the battery LED shows empty

This happens when the cell voltage sags under combined amplifier and Bluetooth radio draw before the indicator threshold triggers. At high volume, the amplifier current spike pulls cell voltage below the clean amplification floor, causing the output stage to clip. The LED indicator lags because it reads average voltage, not instantaneous load voltage. If distortion starts above 20% indicated charge, reduce volume to confirm — if the distortion clears, the cell is sagging under peak draw and the pack needs replacement.