SRS-XB13 | Help Guide | About the indicators

Turns off	The speaker has completed charging.
Lights up	The speaker is being charged.
Flashes slowly	The built-in battery is running at less than 20% and needs to be charged.
Flashes 3 times and turns off	If the CHARGE indicator flashes 3 times and goes off when you turn on the speaker, the built-in battery is empty and needs to be charged.

As long as the speaker is connected to an AC outlet by a USB AC adaptor (commercially available), the speaker's built-in battery is capable of charging itself even while the speaker is turned on.

Depending on the usage of the speaker, however, it may take a long time before charging completes. It is recommended that you turn off the speaker before battery charging.
Depending on the type or specifications of the USB AC adaptor, if you use the speaker at a loud volume, the remaining power of the rechargeable built-in battery may decrease or the speaker may turn off even while the speaker is connected to an AC outlet by the USB AC adaptor. This, however, does not indicate a malfunction. If such a case occurs, turn off the speaker and let the battery fully charge itself before you use the speaker.
If the ambient temperature is extremely low or high, the built-in battery will stop charging itself for safety reasons. It may also stop charging if charging continues for a long period of time. If such a case occurs, bring the temperature up or down to an operating temperature between 5 °C and 35 °C (41 °F and 95 °F), disconnect and connect the USB cable, and then let the battery charge itself once again.

Turns off	The speaker is turned off.
Lights up	The speaker is turned on.
Flashes	Each time you press the -/+ (volume) buttons, the indicator flashes once. When you operate -/+ (volume) buttons and the volume is set at the lowest (0) or highest (31 for music playback/31 for phone calling) level, the indicator flashes 3 times. When the(play)/(call) button and the - (volume) button are pressed and held simultaneously for about 5 seconds and the Auto Standby function is turned off, the(power) indicator goes out and then flashes 3 times. When the(play)/(call) button and the - (volume) button are pressed and held simultaneously for about 5 seconds and the Auto Standby function is turned on, the(power) indicator goes out and then flashes twice.