Hi All- have any of you had any luck with those emergency cell phone chargers? The ones that are just a AA battery inside a tube with a USB port on it? My company gave me one as a door prize at a conference recently, but it doesn't seem to do anything... The droid wakes up kind of when I plug it in, but no charging info displays. I assume a AA battery is just too weak to charge it? Or is it actually charging, just not enough to display the info?