OK, I've just looked at mine, and all of my terminals and all of my power wallwarts for them are clearly marked 20 VAC (1.8 A, 35 W marking on the terminals, 37 VA marking on the wallwarts). Plugging one of the wallwarts into the wall and measuring with a voltmeter showed 24 VAC under no load. I guess it's supposed to sink a little under load. Since it's so clearly marked, why was this a mystery in the first place? What is a little more of a mystery, however, is that the terminals have compartments that seem like they are for batteries, but upon opening them one sees no place to put in standard batteries, but instead some little wierd connectors on short wire pigtails, obviously for some proprietary battery packs. Does anyone have any info on those battery packs? They were rechargeable and charged when the terminal is plugged into AC power, weren't they? I'm guessing that from the fact that they were special battery packs and not standard batteries one buys replacements for at a supermarket or gas station. MS