About this replacement
JBL Wind 3 / Wind 3S — 3.7V Li-Polymer Replacement Battery (GSP903052 02)
This is a 3.7V, 1100mAh (4.07Wh) Li-Polymer replacement battery for the JBL Wind 3 and Wind 3S portable Bluetooth speakers. It slots into the same position as the original GSP903052 02 cell and restores wireless audio playback. Use the dimensions — 49.50 x 30.00 x 8.50mm — to confirm fitment before ordering.
- Wind 3 and Wind 3S shared platform: Both models run the same 3.7V single-cell Li-Polymer configuration and use an identical connector and BMS handshake, which is why one battery covers both SKUs without modification.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on a Wind 3 unit and confirmed the BMS accepted the pack without triggering a protection cutoff. Charge termination and low-voltage cutoff both tripped at expected thresholds.
- Fuel gauge reset after swap: After fitting this battery, run it down to the low-battery indicator before recharging fully — this lets the speaker's fuel gauge calibrate to the new cell and prevents the indicator from reporting inaccurate charge levels from the first use.
Bluetooth dropping at high volume on a fresh battery
At peak volume, the amplifier and Bluetooth radio draw current simultaneously. On a Li-Polymer cell at 3.7V nominal, a combined current spike can pull the cell voltage below the BMS sag threshold momentarily. The BMS interprets this as a low-cell event and interrupts output, which cuts audio or drops the Bluetooth link. Keeping volume below maximum during the first few charge cycles lets the cell stabilise its internal resistance and reduces the sag magnitude.
Speaker shows full charge but audio drops before the indicator reaches empty
This is voltage sag causing amplifier clipping before the battery reads as depleted. As cell capacity degrades — or on a new cell with an uncalibrated fuel gauge — the speaker's indicator lags behind the real state of charge. Under audio load, the voltage drops faster than the gauge tracks, and the amplifier hits its minimum operating voltage first. Run the pack to the low-battery warning, then charge fully to 4.2V in one uninterrupted cycle to recalibrate the gauge.