Jabra Sport Stereo AHB390836 Replacement Battery 3.7V 60mAh

Jabra Sport Stereo / Sport Wireless+ — 3.7V Li-Polymer Replacement Battery (AHB390836)

This 3.7V, 60mAh Li-Polymer cell replaces the internal battery in the Jabra Sport Stereo and Sport Wireless+ wireless earbuds. It fits all variants listed under model 100-55400000-02 and the broader Sport Wireless Plus family. Swap it when the original cell no longer holds enough charge to get through a workout.

• Sport Stereo and Sport Wireless+ platform: These models share the same compact Li-Polymer cell format, connector pinout, and BMS handshake protocol. The AHB390836 cell fits across all variants because Jabra kept the power architecture consistent through the Sport line revision.
• Bench tested on actual hardware: We ran this cell through charge cycles on the Sport Stereo base station and confirmed the BMS completed its handshake correctly. Charge acceptance held at spec across repeated cycles with no cutoff errors.
• First-cycle charging on the base station: After fitting this cell, place the earbud in the base station and let it complete one full uninterrupted charge before use. The headset's talk-time estimate will read inaccurately until the base station logs the new cell's capacity baseline.

Why the Sport Stereo cuts out during a workout on a new battery

The Sport Stereo combines Bluetooth radio draw with audio amplification inside a very small housing — both loads hit the cell simultaneously. A cell sitting at storage voltage (roughly 3.6–3.7V) has not yet reached full working capacity, so voltage sags under that combined draw and the BMS trips the output. This isn't a fault with the replacement cell. One complete charge cycle through the base station brings the cell up to its full voltage window and the cutouts stop.

Base station showing full charge but earbud cuts off after a few minutes

This happens when the cell arrives at storage voltage and the base station's charge circuit reads it as already full. The base stops pushing current before the cell actually reaches 4.2V. Pull the earbud out, leave it off for 30 seconds, then reseat it in the charging cradle — this resets the charge detection circuit and forces a fresh charge cycle. Confirm the charge LED cycles through its normal sequence before removing the earbud again.