Batteries, yes... but maybe at the bottom of my list for now.
I had a bit of a "DUH!" moment while thinking about the various transformer suggestions here. These servos and drivers I'm working with came from an industrial system that I acquired, and I actually _have_ a 1kVA transformer already that came with it. I had overlooked the possibility of using it, or at least considered it a last resort, because the input voltages don't match what's available in my house. Just to remind you folks overseas, that's 120VAC and 240VAC. The former is much easier to work with since our "standard" power outlets are 120VAC.
The transformer is wired for two input voltages, 208V and 460V. When I input 123.1VAC to the 208V terminals, I got 19.5VAC out. Close, but close enough? I was thinking I might be able to get away with 240VAC (15% higher than the spec sticker), and it should yield 38VAC. I'm not one to disregard recommended ratings, but I don't think I'd be pushing it too far on this one. Anyone think I'd be foolish to try? Anything specific to watch out for?
Also, I looked at maybe rewinding or partially rewinding this transformer. It looks possible, but if I can use it without changes that would be my preference.
Pictures attached show the spec sticker, as well as the size of this beast.