I'm pretty inspired by this.
I have a spare Mean Well HRP-600-15 laying around I may play with to try something similar:
https://www.meanwell-web.com/en-gb/a...t-hrp--600--15
These have adjustable voltage output and run happily on a pretty wide range of either AC or DC voltage. Just a matter of figuring out how best to provide 120VDC+ or an AC power source. I imagine if I took something like an old UPS and strung some 12v batteries in parallel, the two conversions wouldn't be all that efficient but it would be quite flexible. Just connecting 11+ batteries in series to get adequate DC voltage would be better, but then I have (potentiality) a lot of weight, and high voltage DC...