This piece covers How to Charge Sony SRS XB30. Do this easily through the micro USB power in port, shown in the pictures below. Note that you can still play your XB30 as it recharges, without raising the charging time by very much.
First, pick a powerful enough USB adapter, as no charger comes with this Sony Bluetooth speaker.
Next, connect a medium to high current USB cable. Use one between the speaker and that adapter that easily carries 1.5 amps. Note that the XB30 comes with a short micro USB to USB-A cord.
Then, plug the charger into a working wall outlet.
Finally, after four hours or so, your XB30 finishes recharging. So it’s ready to play once more for up to twelve (12) hours before needing another charge-up.
How to Charge Sony SRS XB30: Step by Step
1. Choose Correct Size AC or Car Adapter
Firstly, the charger you use should provide 5 volts at 3 amps (15 watts) for fastest results.
2. Power OFF the Unit to Continue with How to Charge the Sony SRS XB30
Note that the SRSXB30 still charges when running. But the speaker might charge a trifle faster when turned OFF. However this depends on how much above-and-beyond recharging headroom that your charger supplies.
3. Plug the Power Cord into the Speaker
Then open the water resistant port door.

So this exposes the barrel type DC input input port as we see next.

Then, plug the small end of the cable into the port on the back of the speaker.

4. Plug the Adapter into a Working Wall Receptacle to Continue with How to Charge Sony SRS XB30
Connect the mains end of the adapter to a working AC outlet. So we plug ours into a power strip surge protector here.

The status lamp lights up solid orange on the speaker. Now there is no visual battery status gauge that shows percentage of charge. But the glowing CHARGE lamp does show that charging is occurring.

5. Let the XB30 Charge Until the Orange CHARGE Light Goes Out
Then full battery charging is complete when the solid glowing CHARGE lamp turns OFF.

6. Unplug the Cable from the XB30
Also, close the port cap to maintain water resistance.

7. Done with How to Charge Sony SRS XB30 !
At last, we have now fully charged this Sony speaker.
Finally, repeat this recharging every twenty-four (24) hours of play. Or do it any time the 30 goes dead, to keep the battery in top condition for years to come.