Originally Posted by Cyril

This reply may be of no use whatsoever so be forewarned.
I don't own a garmin touring +, but I do have an edge 705 and an edge 200.
I sucessfully charge both of these as i'm using both units with the gomadic battery pack
(uses 4 AA batteries). the gomadic also comes with a USB cable designed for charging and not for transfering data.
This could be the crux of your problem. If you use a data cable on the 705 or the 200 strange, non-charging things happen...like random power downs.
The same could be true of the Touring +.
OTOH, each Garmin seems to be designed to provide a unique user experience, so this may not help you at all.