The JBL Boombox 1 has a row of LEDs across its lower front panel. These display battery fullness and charging status. In short, the JBL Boombox 1 battery indicator shows how full the battery is whether charging or not.
How to Read the JBL Boombox 1 Battery Indicator Lights
1. All LEDs OFF
When you power down the Boombox 1 with no charger connected, no lamps glow, as shown next. The lamps also remain dark when the charger IS present but charging is complete.
2. JBL Boombox 1 Battery Indicator: Shows Recharging Progress
There are five lamps that light in succession as the speaker battery charging advances, as shown in the next picture. This speaker is charging when you see one of these lamps blinking white. When the battery is at almost complete discharge, the light on the far left blinks red. Then it flashes white once you begin charging.
Then as charging continues, that lamp stops flashing, and assumes a steady white glow. At that point, the next lamp to the right starts blinking white.
3. When All Lamps Light Up Solid, Charging is About Done
As Boombox 1 charging progresses, more of these lamps light up solid. Plus, the flashing white LED gradually moves further to the right until that blinking reaches the last position.
Battery charging is almost complete when all but the last of the battery indicator lamps light solid. The last one continues to blink for several minutes. Again, you know that charging is occurring if one of the charge level lamps is flashing white.
The battery recharge cycle on the JBL Boombox 1 finishes when all indicator lights turn off, as shown above. Thus, the battery is no longer charging when all lamps are OFF. Even with the AC charger still connected, no lamp glows when battery is full.
4. The JBL Boombox 1 Battery Indicator also Shows Battery Fullness when Not Charging
Lastly, when unplugged from the charger, what was the charging indicator becomes the battery indicator. The more lights lit, the fuller the battery. The fewer glowing lamps, the less speaker run time remains. These lamps show battery status for a brief time after power up. Or they also light whenever you press any of the buttons.
Furthermore, to save power, these lamps go dark after some seconds. So to see how much battery charge remains, just press the volume UP or DOWN buttons. The lamps will then light up again, and display battery status.