USB adapters used to charge Garmin GPS


Has anyone used one of the USB adapters that plugs into the cigarette adapter to power a GPS? The one I have tried the GPS thinks it is plugged into a computer and won't show the maps.
Any help would be very appreciated. Want to shorten the cord up and get rid of the bulky charger when I have it mounted on a motorcycle.

Try here

I do not have experience, but take a look here to see if this will be of any help.