5V 2.1A Car charger XKY-002



Official specifications:

• Made of high quality durable aluminium alloy and plastic.
• Dual USB, can charge two mobile devices at once.
• Support to plug into any car power outlet.
• With Blue LED indicator light.
• Output: 2.1A & 1.0A.
• Universal USB port works with most USB cables.

I got it from ebay dealer: tonsee_star



The charger was packed in a plastic bag inside an envelope, very common for Ebay.







Measurements

• Both USB outputs are coded as USB charger (DCP)
• USB outputs are in paralle.
• There is a blue light inside the charger, it will light up the bottom part of the ring and bottom USB connector.
• Power consumption when idle is about 4mA on 12V and about 3mA on 24V
• Weight: 20.3g
• Length: 72mm
• Diameter: 34mm

The 1A output can only deliver 0.8A, not very promising.



The charger is seriously underpowered, the 2.1A output is also about 0.8A



Using the two outputs in parallel it is still 0.8A



Higher input voltage do not help.



Even 24V is the same.




The 5V output work down to 10V



The idle current consumption is low and varies a bit with voltage.



With the maximum current at 0.8A, I decided to run a load test at 0.7A, the worked for about 8 minutes, them the charger turned off.



Reducing the current to 0.5A was better.
The temperature photos below are taken between 30 minutes and 60 minutes into the one hour test.



HS1: 48.2°C



HS1: 45.5°C



Noise at 0.5A output is 12mV rms and 106mVpp





Tear down



I could pull the front off and then get the electronic out.



The circuit is very simple with one switcher IC (AD85063D), a diode and a inductor and two capacitors.










There is nothing on the other side. The soldering of the spring and power minus input is not very good.





The board with the USB connectors has the blue led and a resistor for it in addition to the dual USB connector.
The board supports two leds to get a more uniformly lit ring.







Being a 12V device there is no need to test with high voltages.



Conclusion

This charger may have been fine at the start of the USB era, but not today, the output power is way to low and it is missing a input fuse.



Notes

The charger was supplied by a reader for review.

Read more about how I test USB power supplies/charger
Compare car chargers and other DC supplied chargers