I too have used my 45W adapter with my 17-inch PowerBook. It does charge more slowly, but it works normally. The official word from Apple in the Developer Documentation for the 17-inch: "A device’s ID voltage limits determines how the PMU identifies the power adapter. The PowerBook G4 17-inch computer is designed to use the 65-Watt Apple Portable Power Adapter which ships with it. Although you can use a 45-Watt Apple portable power adapter with a 17-inch PowerBook G4 computer, it may not provide sufficient power during some activities and power may be drawn temporarily from the battery. Should the battery become discharged, you may need to plug in the 65-Watt Apple Portable Power Adapter that came with the computer in order to start it up." There isn't any mention of similar things for the 15" PowerBook, but presumably it should work fine as well. Just make sure you do it while you're still under warranty, just in case something breaks... ;-) Paul Russell <prussell at arc-software.com> writes: > The older supplies were 45 W and the newer supplies are 65 W. Having > invested in a couple of extra 45W power supplies for my old TiBook I > was curious as to whether they would work with my new 17 incher and > they seem to be fine. They get a little warm, but so far I haven't > had any major fires. > Kynan Shook kshook at mac.com http://homepage.mac.com/kshook/index.html