Read the fine print on the chargers and it will tell the output of each, the touch and diamond ac ones are both 1amp I believe which should be higher than most usb sources usually, but my car .5 amp actually puts out more than my wall chargers, you can monitor your charging rates with nuepower Cpl I use the V1.52 cab but there is also a diamond download lower on the page that installs fast charge also.
It tells a lot of info including power use and power charging.
My diamond gets hot enough to fry eggs on with the fast charge cab installed, but my charge rates almost doubled.
thanks no2chem