After last week's article on PowerBook AC adapters was published (see "Comparing Three AC Adapters" in TidBITS-803), I've received several messages from people about the MadsonLine MicroAdapter and the MacAlly adapter - specifically, about the amount of power they provide.
I wrote that the MicroAdapter wasn't recommended for use with newer PowerBooks (the 1 GHz PowerBook G4 Titanium, and all of the 15-inch and 17-inch PowerBooks) because it provides only 45 watts of power, compared with the 65 watts provided by the adapter Apple ships. Several people wrote in to say they were, in fact, using the MicroAdapter with those machines, and that it appeared to work fine - though some reported the adapter getting "pretty warm." One person suggested the overheating was the main reason MadsonLine had to disclaim using it; another that the higher wattage requirement on newer PowerBooks was only under peak usage, and that when performing less-intensive tasks a lower-power adapter works fine.
The comment that struck me the most, though, was the report of burning out two MicroAdapters one after the other. Unfortunately, I haven't been able to test for myself; my MicroAdapter died an honorable death when the tip was crushed in an accident.
I can claim personal experience with the MacAlly adapter, though; I'm using it as I type this now, in fact. As more than one person pointed out, the power specs for the MacAlly are similar to the MicroAdapter; only 48 watts provided, less than what's officially needed to run the newer PowerBooks. I hadn't ever looked at the specs myself, since the reseller I bought it from sold it for all PowerBooks, and it had always worked fine with my 15-inch PowerBook G4. Because of this, I can credit the reports of people running a MicroAdapter on the newer PowerBooks without trouble; however, I'd still be cautious about doing so, because of the report of burnout.