The Product

XTAR sent me over their new EU4 to review. This is a USB power supply with 1 QC3 port, 2 USB-A ports, and a single USB-C port. It also has a display that can show status, voltage, current, and capacity has been output.


I've had a very similar product to this tucked away inside my nightstand for longer than I can remember, and it's one of the handiest pieces of tech I own. This one adds USB-C and a display, both of which are great upgrades, and pretty unique on the market.
I wish this didn't make you pick between the ports and could access them all at once, or was at least a bit better at intelligently selecting ports - but overall I really like it, and I'm glad XTAR is getting into this market. I'm also extremely excited to see another manufacturer embracing USB-C.

Physical Dimensions

The charger itself measures 92.8 by 65.8 by 28.7 mm. There is no external power adapter or brick required, which is awesome.


The charger is constructed entirely from dark grey soft-touch plastic. The front of the charger contains the button, and the back-lit LCD display. The brand and product names are also screened onto the device here.
The left side houses the AC-in port.
On the right hand side is the collection of outputs from this charger, all clearly labelled. From top to bottom, there's a QC3.0 USB-A port, two 2.4 A max USB-A ports, and a USB-C port.
The top and back sides of the charger are both bare.
The bottom of the charger is filled with labeling. This includes the input and output specs, as well as all the regulatory labels.

What's Included

The kit you get with this is pretty straight forward - just the charger, the required AC power cord, and some paperwork.


The charger has two modes that are switched by tapping the button on the front. In the first mode, all three USB-A ports are active. In the second mode, the QC 3.0 USB-A port and the USB-C ports are active. There is no mode in which all 4 ports can be used at once.
The button is also used to turn off the light in the display, if you happen to be using it in a dark room - just long press.

USB-A QC 3.0 (Port 1)

The top USB-A port is always active, as indicated by the "USB 1" label at the top left of the display.
With standard use, this port delivered up to 3.6 A before the over-current protection kicked in. The voltage was extremely stable, barely dropping at all as the current draw was increased.
Triggering QC 3.0, we can see that the charger has no problem delivering up to 1.5 A at 12 V, either. The power delivery dropped off after 1.5 A, but I believe that may be due to my tester trying not to cook itself. Once again, voltage was very stable throughout the test.
Even during this test, delivering over 18 W, the charger didn't get warm to the touch.

USB-A 2.4 A (Ports 2 & 3)

Ports 2 and 3 are active by default. Even if the charger is switched to USB-C mode, these two ports will reactivate when the device in the USB-C port has completed charging. When these are active, "USB 2/3" is shown in the center of the top of the display.
Testing these two ports showed nearly identical performance, as expected. Over-current protection kicked in at 2.75 and 2.70 A respectively, with both ports maintaining good voltage throughout the test. Port 3 showed the voltage dropping down to about 4.8 V right before terminating the charge, but this shouldn't damage any connected devices.

USB-C (Port 4)

USB-C is probably the single most exciting feature of this charger for me. The port needs to be activated by pressing the single button on the charger, and once active the top right of the display shows "Type C". 
The charger will not detect if a USB-C device is inserted when it is in the default mode without pressing the button. If it is switched to USB-C mode and no current is being delivered through the USB-C port, it will switch back to the extra USB-A ports. This is true even if there are no devices connected to ports 2 and 3.
Unfortunately I don't have the equipment needed to test USB-C charging as thoroughly as USB-A, but I can confirm that it had no issues activating rapid charging on a Pixel 3, which confirms that they have implemented USB-PD.



  • Extremely handy device
  • USB-C is great
  • Display can be useful to show charge rate or overall capacity (though it's not the ideal tool for the job)
  • No external power brick is great
  • QC 3.0 is great for charging mobile devices
  • Doesn't get hot during use


  • USB-C needs to be manually triggered with each use
  • Can't use all 4 ports at once, even at a reduced rate