Laurent > Did someone else tried something along these lines? I was looking at something similar with the microsolar AAA to usb (with small solar panel). In theory if you leave it in the sun where it won't get too hot it will charge back up over a day or two. It is only AAA so it might not be able to do an empty-to-full charge on the n800. http://www.21st-century-goods.com/page/21st/PROD/SM400 I have a usb/power adapter but not the microsolar yet. I noticed if you run the n800 down until it turns itself off, then it will get into a sort of reboot cycle when trying to charge it from usb. It doesn't seem to be taking a charge while it does that. Maybe it's trying to pull more than 500mA. Brad