The front left view of the Sony SRS XB21 speaker.

Sony SRS XB21 Battery Indicator

The Sony SRS XB21 battery indicator is an LED in the rear button / port panel on the speaker. Find it just to the right of the USB input port.  This displays battery status. E.g. Whether it’s draining or charging, or whether it’s critically low or not when discharging.  But it neither reads out charging progress, nor exactly how full the battery i. But it does pulse orange when the battery hits close-to-dead. So in this post, we explain how to read this battery indicator lamp on the XB21.

To get a more precise readout of battery percentage, see below.

How to Read the Sony SRS XB21 Battery  Indicator: Detailed Steps

1. The Lamp is OFF 

The battery lamp is dark in the following situations:

    1. When you power down the XB21 with no charger connected.
    2. When the charger IS present but the battery is full.
    3. And finally, this light is OFF when the speaker itself is ON but the battery is not low. Specifically, this light is dark as long as the battery does not yet need charging.
The dark -CHARGE- light on the Sony SRS XB21 speaker.
Sony SRS XB21 dark -CHARGE- lamp.

2. The Sony SRS XB21 Battery Indicator Flashes Orange

With the charger unplugged, the XB21 running, and the battery very low, this light starts flashing orange.  This means that the speaker will shorty power off due to a dead battery. Therefore you should put it on the charge soon to avoid play cut outs.





3. This Lamp Also Functions as a Charging Light

This LED also lights steady orange (no blinking) as the XB21 recharges, as we see in the next picture.   On this speaker, the light glowing is the only visual way of telling that charging is occurring.  But it does not show how far along the recharging is, until it actually goes dark.

Picture of the -CHARGE- light glowing.
The -CHARGE- lamp glowing.

Also note that this light should never blink on and off during recharging.  If it does, then either your charger is not working or your USB cable is faulty. Or the speaker itself may be faulty.

4. When the Light Goes Dark While Charging, Then Charging is Complete

As speaker charging continues, the light keeps glowing. However eventually, battery charging completes. Then the lamp goes dark to show this.  It is then OFF whether the speaker itself it ON or OFF. Note that the light will go dark too, if you disconnect the charger before the charge cycle finishes.

5. The Sony SRS XB21 Battery Indicator Is Not a Charge Remaining Meter

When unplugged from the charger, this light becomes the battery charge left indicator.  Well sort of.  So if it is dark when the speaker is ON, then the battery has some play time remaining. However you cannot tell exactly how much. If it flashes though, then you can know for sure that the battery is nearly dead.

Reading Battery Percentage

However, on this speaker, you can get a more precise reading on the percentage of battery charge left.

Picture of the -BATT- button.
The -BATT- button.

Just press and hold the Phone-BATT button until the speaker says the remaining power percent value in a female voice.

Other Posts About the Sony SRS XB21

    1. Factory Reset Instructions
    2. How to Connect to iPhone
    3. The Buttons Explained
    4. How to Turn OFF
    5. Telling if the Sony SRS XB21 is Charging

References for Sony SRS XB21 Battery Indicator

    1. Sony SRS XB 21 Official Product Page
    2. Where to Buy the Sony SRS XB21