I don't know if this has been already mentioned on this thread, since I have just discovered this site, but I operate my 1520 from a 12 V battery on my sailboat without any apparent problem. I've used it mainly to get radio weatherfaxes. I just bought a 22 mm female plug from Radio Shack, wired it to the 12 V power supply and stuck it into the jack on the back of the GRiD (next to the battery pack). One trhing that bothers me when receiving faxes is the screen going dark after a fes seconds. Anybody knows how to disable this battery-saving function ? (which I don't need since the 1520 consumes only 1 Ah, which is peanuts for a 100 A deep cycle battery). john