The JBL Wonderboom has two light LEDs that may be flashing. There’s the Bluetooth pairing lamp. Also there’s the charging lamp, in the Power button. These are both on the top of the unit. The pairing lamp flashes when pairing mode is active, and the charge lamp flashes when the JBL Wonderboom is charging. Details on both of these Light Flashings follow.
JBL Wonderboom Light Flashing: Pairing Mode Active
When the Pairing button flashes white, the JBL Wonderboom is in discovery or pairing mode.
JBL Wonderboom Light Flashing: During Charging
The Power lamp flashes white while the JBL Wonderboom is recharging.
This light flashes in a gradually dimming and brightening pattern. On this speaker, this LED is the only visual indication that charging is happening. But it does not tell how far along the charging is.
It flashes during charging whether the JBL Wonderboom is OFF or ON.
As charging continues, the light keeps slowly flashing white. Furthermore, battery recharging is over when the lamp goes out, or turns solid white. It turns OFF when the speaker is OFF, and switches to a solid white glow when the speaker is ON.
The battery recharge cycle finishes when the speaker status lamp turns OFF. Even with the AC charger running, the lamp does not glow when battery is full. Not unless the speaker itself is running.