Razr "Unauthorized Charger"

Thread view:

Enable EMail Alerts

Start New Thread

Thread rating:

Z Man - 24 Oct 2006 12:51 GMT

I bought a car cord/charger at a computer show. It fits perfectly, but I get
a message on the phone that reads "unauthorized charger". I have done some
research and found that this occurs frequently with after-market chargers,
and sometimes even with OEM charges. Usually, folks raise this question when
they plug their phone into the USB port on their computer. I am only
concerned with car use and charging. Regardless of the message, will the
phone still drawer power from the car? Will it still charge?

Reply to this Message

SteveC - 26 Oct 2006 05:15 GMT

Yes

>I bought a car cord/charger at a computer show. It fits perfectly, but I
>get a message on the phone that reads "unauthorized charger". I have done
[quoted text clipped - 3 lines]
>am only concerned with car use and charging. Regardless of the message,
>will the phone still drawer power from the car? Will it still charge?

Reply to this Message

Dennis Ferguson - 26 Oct 2006 21:46 GMT

> I bought a car cord/charger at a computer show. It fits perfectly, but I get
> a message on the phone that reads "unauthorized charger". I have done some
[quoted text clipped - 3 lines]
> concerned with car use and charging. Regardless of the message, will the
> phone still drawer power from the car? Will it still charge?

Here's the problem. The USB specification limits the minimum power
available from the interface voltage pins to 500 mA at 5 volts, or 2.5W.
The GSM version of the RAZR, which first adopted the USB charger cable,
can apparently live with that, but the CDMA phone is more power hungry and
needs more than 2.5W to charge. The chargers supplied by Motorola will
deliver significantly more than 500 mA, and as a practical matter a lot
of other USB chargers and interfaces will too, but with the latter you
can't count on them to support more than the standard requires. While
the phone still uses a standard USB jack for the charger, the power
requirement is non-standard.

The "unauthorized charger" message is hence telling you that the power
output of your charger is significantly lower than a Motorola charger
would provide. It may or may not still charge the phone, you'll have
to try it to see. If it does charge the phone it will take longer to
do so than a higher power charger would. If you were sold this charger
explicitly for use with that phone you got shafted, but otherwise it
is just an unfortunate incompatibility caused by the non-standard
power draw those phones need from their USB interface.

Dennis Ferguson

Reply to this Message

Mike S. - 27 Oct 2006 00:21 GMT

>> I bought a car cord/charger at a computer show. It fits perfectly, but I get
>> a message on the phone that reads "unauthorized charger". I have done some
[quoted text clipped - 23 lines]
>is just an unfortunate incompatibility caused by the non-standard
>power draw those phones need from their USB interface.

I'm not sure that's all there is. My wife has a V3c, and I tried a
Zip-Linq USB power supply rated 5V @ 1000 mA and got the same error
message.

Reply to this Message

vicentezamora - 20 Nov 2007 15:17 GMT

This may solve the riddle for whoever is still reading these posts. For
the past year and a half I have been charging my RAZR V3m from Verizon
with a mini-USB cable, any cable, my digital camera, the USB floppy,
etc, I never really checked whether all of them were 4pin or 5pin, so I
don't have any further information about that.

So today I come in to work and plug in my cell to the mini usb cable
that I have been using for at least 2 months (in this particular PC) and
I get the "unauthorized charger" message, I think.. "WTF?" this has been
working all along. So I do a little reading in here and a couple of
other forums and it dawns on me that I changed me USB port on that I was
connecting to recently. I plug in the USB cable to the other port that I
was using and voila! the PC recognizes it and loads the drivers, etc etc
and now it's charging.

For whatever reason, the 6 USB ports in the back of this PC are split
in 2 and 4, on the group of 2 I have a laser printer and on the group of
4 I have a wireless keyboard. Maybe the printer was pulling too much
juice for the USB to be able to give it to the phone, and obviously, the
wireless keyboard doesn't pull in too much power.

So there it is, if you have a mini-USB cable that is able to provide
power to other devices (USB floppy, etc), it should be able to charge
your RAZR provided the USB port gives enough power (voltage, amps,
whatever it is, i am not an EE). Try different USB ports from your
computer, the ones at the back, the front ports and start with a direct
connection to the PC instead of using a hub (although an externally
powered hub may work too).

I imagine that's where the 5pin USB comes in vs the 4pin, the 4pin
sounds like it's 1pair receive and 1pair transmit, so only data comes
through, but the 5th wire may provide the electrical.

If you want to get a cheap mini USB cable, try getting a Dell mini USB
cable on ebay, they come in 3ft and 5ft, I got a bunch of 3ft at less
that $1 each plus shipping and I have one on each laptop bag, one in my
car and 2 in the office.

My 2cents, I hope this helps anyone.

Vince

------------------------------------------------------------------------
View this thread: http://www.wirelessforums.org/showthread.php?t=9545
http://www.wirelessforums.org

Reply to this Message