The right front view of the Sony SRS xB31 speaker.

Sony SRS XB31 Charging Instructions

This piece gives Sony SRS XB31 speaker charging instructions. Recharge this speaker at will through the micro USB DC power input port, behind the water resistant door in the back of the unit. See it in the pictures below. Note that you can still play your XB31 while charging, without upping the recharge time very much, especially if you are using a full-current USB charger. But for the absolute fastest charging possible, it’s best to turn the speaker off as you recharge it.

Sony SRS XB31 Charging Instructions, Summary

First, the unit comes with an adequate USB-A to micro USB charger cord. But you must provide a beefy enough USB power supply with a USB-A female connector, to plug that wire into.  This speaker charges most quickly with about 7.5 watts (5 volts at 1.5 amps max). Thus any full-current USB 2.0 AC or car converter should work well with this speaker.

At any rate, once you select the charger you will use, plug it into a working power outlet, connect up the charging cable, and charge, charge charge !

Then after five hours, your XB31 finishes recharging.  Then it’s ready to play once more for up to twenty-four (24) hours before needing another fill-up.

Sony SRS XB31 Charging Instructions, Step by Step

1. Choose Properly Sized AC or Car Adapter

As mentioned, the charging adapter you use should offer 5 volts and at least 1.5 amps (7.5 watts).  Here, we use the Key Power model HDD15-3-PD USB power delivery system along with a thick-enough USB supply cable.

2. Open the Port Cap Door

Use a fingernail, dime, or small screwdriver to lift open the waterproof seal port cover on the XB31.

Picture of the closed port door on the speaker. Sony SRS XB31 Charging Instructions.
The Sony SRS XB31 speaker with closed port door.

See the opened power port compartment in the next picture.  Take care not to scratch the delicate seal around the inside edge of this door.

Picture of the micro USB DC input 5V port.
The micro USB DC input 5V port.

Prying open this door exposes the USB charging port inside, as shown in the last picture, pointed at by the green arrow.

3. Power OFF the Speaker to Continue with Sony SRS XB31 Charging Instructions

Note that the SRSXB31 still charges when powered ON.  But depending on how much above-and-beyond recharging amperage your charger delivers, the speaker might charge somewhat faster when not running.  It will definitely charge more quickly when you’re not playing it at louder volumes.

4. Plug the USB Cord into the XB31

Then, plug the matching end of your charging cable into the DC input micro USB port on the speaker, as we see in the next shot.

The orange glowing -CHARGE- light.
The -CHARGE- lamp glowing orange.

Warning: Only use the micro USB port for charging the speaker.  Do not feed power into the USB-A port near the left side in the port compartment.  The larger connector is for DC output only, and is used for power bank purposes. So, applying external power to THIS port will not only fail to recharge the XB31 battery. But it could also damage the electronics inside the speaker.

5. Plug the Other End of the USB Cable into your Charger Adapter

If the supply you use has a removable wire, then be sure to connect the matching end of the USB power cable to the AC or car adapter you have.

6. Plug the USB Adapter into a Working Wall Receptacle to Continue with Sony SRS XB31 Charging Instructions

Now that we connected the XB31 and our adapter, we then plugged the mains end of the supply box into a working AC outlet, as shown next. We connected ours to a surge protecting power strip.

Picture of the speaker connected and charging.
The speaker connected and charging.

The CHARGE lamp then lights up solid orange on the speaker. And while no battery status gauge shows percentage of charge, the glowing lamp means that charging is indeed occurring, as we see next.

The orange glowing -CHARGE- light. Sony SRS XB31 Charging Instructions.
The -CHARGE- lamp glowing orange.

7. Let the XB31 Continue Charging Until the CHARGE Light Goes Dark

Full battery recharging concludes when the CHARGE lamp turns off, as shown next.

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

8. Unplug the USB Charging Cable from the Speaker

9. Fully Close the Port Cap / Door 

Note that unless you seat the port door fully, water may flow into its power in / out ports. And, since water and electronics do not work well together, getting those connections wet might degrade the delicate contacts inside. So be sure to press this door closed with enough pressure to fully seat it, for maximum protection against moisture.

Picture of the closed port door once again.
The closed port door.

10. Done with Sony SRS XB31 Charging Instructions !

We have now fully charged our XB31 speaker.

At last, repeat this recharging every (up to) twenty-four hours of play time, to keep the battery in top working order for years to come.

Other Posts About the Sony SRS XB31

    1. Sony SRS XB31 Battery Indicator Explained 
    2. Sony SRS XB31 Hard Reset Instructions
    3. How to Connect Sony SRS XB31 to iPhone
    4. Sony SRS XB31 Button Functions Explained
    5. How to Check XB31 Battery Life

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    1. Sony SRS XB31 Official Product Page at

Revision History

    • 2021-10-19: First published.