On Fri, 31 Jan 2014 07:35:57 +0000, Danny D'Amico wrote:

"With a standard USB data cable the phone recognizes it as a USB charging
source and only pulls 500 mA. You can get "charging only" cables
allowing higher (still safe) amperage"

Googling for what the difference is between a data & charging cable,
I find this reference:

http://forums.androidcentral.com/sam...harger-s3.html
Which says:
The two types of cable are a "charge only" cable and a full data cable.
In order to distinguish which type of port they're connected to and therefore
know how much power can be drawn phones examine the two inside "data" wires
on the USB connection. If they are shorted together the phone says hey I'm
plugged into a charging port and can draw max amps and it reports it as "AC"
--if they are not shorted then it limits amp draw to 0.5amps and reports it
as " USB". Note that some wall wart modules short the data pins internally
--with those you can use any cable and pull max. Others don't so in order
to pull over 0.5amps you must use a special "charging only" USB cable that
does the shorting in the cable--these will NOT work for data usage.

Apple phones do something similar but instead of shorting the data pair
they change the voltage on one data wire.