Started: 11/10/2010 * Last Update:

    NOTE: This device, SKU#21890, is no longer being sold, last checked: November 2013.

SKU number: 21890 was supposed to be a dual powered (12-14V DC from your car or from 120-240V AC) USB power supply able to supply 5V DC at 500mA.   Deal Extreme   just enter an SKU# in the search box.

NOTE: This device, SKU#21890, is no longer being sold, last checked: November 2013.

Here's is what they had up about this device, #21890:
  • Slim and compact design - True, I like it
  • Features US power plug and car power plug - True.
  • Perfect charger for Apple iPod, iPhone 2G and 3G, and any USB gadgets
    FALSE it only works for items able to accept 5.4V & no more than 100mA of current.
    NOTE: An iPod nano requires 200mA & this unit drops down to 4V and the nano doesn't accept it as a charger.
  • 500mA 5V power output ensures your device gets enough power and receives quickly charging time - FALSE! see below.
  • 100V~240V AC power input, 12~24V Car power input
    ??? I can only confirm to 120V AC and 12-14V DC.

And the truth about the SKU #: 21890 device was...

  • It's a nice package, I may be able to use it for something useful.

  • The blue LED is nice, I'll at least save those.

I tested four of these items to see if I could make them work. Here is what I discovered.
  1. A "working" unit puts out ~5.4V with no load (nothing plugged into the USB power port). I had one that put out 7.1V.

  2. With a 200 mA load (about equal to charging and playing an iPod Nano) the voltage drops to 4.0V Which shuts down the iPod charging, it need > ~4.5V min
  3. - At this point I took four of them appart, the 7.1V one and three others ~5.4V

  4. A 33K Ohm resistor can be put across the voltage resistor to drop the voltage to ~5.1V

  5. A wire can be attached from the LED 2.5V point to the two data (center) pins to satisfy the USB power specification and my iPod nano then tried to charge, but because of #2 above it did not.

The bottom line is that without a redesign and replacement of limiting parts this unit is almost worthless. There are devices out there that can use the poor voltage stability and low current of this device but if I were you I wouldn't waste the money.

This was a very nice idea but with extremely poor design and engineering behind it.

If you know that your device can use 5.4V (and I would first check the unit to be sure it is safe to use) and ~100mA to charge or work, then this unit will work for you. But, if you expect it to work with your iPod or iPhone you will be disappointed.


  Return to the: