This piece covers how to charge the Sony Cube Speaker. Do this easily through the micro USB power in port, shown in the pictures below. Note that you can still play your cube as it charges, without increasing the recharge time by much.
First, pick a strong enough USB power adapter, as no charger comes with the Sony Cube Speaker. Next, connect a medium to high current USB cable between the speaker and that adapter (the speaker 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 cube finishes recharging. So it’s ready to play once more for up to twelve (12) hours before needing another recharge.
How to Charge Sony Cube Speaker: Step by Step
1. Choose Correct Size AC or Car Adapter
The charger you use should provide 5 volts and at least 0.5 amps (2.5 watts). This option though yields much longer charging times. But ideally, you want a 1.5 amp charger (7.5 watts) for the fastest recharging. So here, we use a Key Power model HDD15-3-PD USB power delivery system. Now as mentioned, this speaker needs roughly an amp and a half current to recharge fully in a reasonably short time. So this charger supplies way more than enough power to do the job.
2. Power OFF the Unit
Note that the cube still charges when powered ON. But depending on how much above-and-beyond recharging capacity your charger supplies, the speaker might charge a little faster when turned OFF.
3. Plug the Micro USB Cord into the Speaker
Then, plug the small end of the cable into the port on the back of the speaker, as we see in the next shot.

4. Plug the Other End of the Cable into your Charger Adapter to Continue with How to Charge Sony Cube Speaker
Next, connect the large end of the cord to the AC or car adapter.
5. Plug the USB Adapter into a Working Wall Receptacle
Now that we connected the cube and our adapter, we then plug the mains end of the adapter into a working AC outlet, as shown next. We plugged ours into a surge protecting power strip.

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

6. Let the Cube Charge Until the Orange CHARGE Light Goes Out
Full battery charging is complete when the solid glowing status lamp near the bottom of the speaker turns off, as shown next.

7. Unplug the Micro USB Cord from the Unit
8. Done with How to Charge Sony Cube Speaker
We have now fully charged this Sony cube speaker.
Finally, repeat this recharging every twelve hours of play, to keep the battery in top condition for years.