that's the question, right? i don't know what the problem is, all i know is that i don't like it. i will try a 1amp charger when i'm in the car next...
Judging from the posts, the problem exist in all Android phones. I have seen posts from all types of users. I did several posts months ago testing several placements in the car and different chargers. I have a D1. It was running 2.1 at the time and 2.2 now. No real difference. I think trying to cram as many features as these phones have just creates heat when you are using a power hungry app like Nav.
I am a long way from an Android expert. I do not remember what the standard VZW charger puts out, but I think it is less than 1 amp. But, I am more well versed in batteries and charging than most. Anytime you increase battery charging rates, you create more heat. Charging heat IMHO is the biggest culprit in this issue. 1 amp may make the situation worse. On long trips I can extend my GPS run time by going on and off the charger. And when I am on a long trip... I shut the GPS off for part of the hours that I am on the interstate and I know I do not need to get off for several hours.
Droid does some cool and amazing things. Yet it does not do some basic stuff that has been stock on most phones for years. It makes me think the Google developers were marooned in some kind of a 1977 LOST flashback/flashforward/sideways combo reality gameshow