Originally Posted by mikebontoft
damn you beat me to it.
I don't know about iphones, but with android you can do something called usb fast charge. If you arent using a factory charger, its less amperage unless you enable fast charge.
yes this and most usb chargers that plug into the 12v only do 5watts (5v@1amp) as the usb is set as data, which will cause them not to charge as fast (or slowly drain under full load.) Pretty much your phone sees it as a usb instead of a wall charger.
I bought this one
from Amazon and the one reviewer even mentions how he cracked it open to solder it so he can get full 2amps out of
I just like it for its small profile and dual usb.