on 1 December 2010
I have used this "charger" twice, once on a 45mins journey and once on a 1hr journey. I had rechargeable batteries in my Oregon, but at the end of both journeys the power bar was still sitting on red and on unplugging I got the "Battery low" message.
It does provide an in-car power source, saving on internal battery usage, but I don't think it does what it says on the tin, ie charges batteries. I already have an in-car power supply for my Oregon, so this product appears to be redundant. (Incidentally, like most other people I also have an in-car charger for my mobile - which DOES charge my mobile).
on 7 November 2011
This item would not work with my Garmin Oregon 400T, the screen froze and even after disconnection, it took some time to reset it. I did not retry it for fear of damaging the device.