I actually tried and sort of stop thinking about it. I got a cheap CyberPower 700VA UPS (1U rack mount), and removed the power interrruption alarm (so it doesn't beep when it goes to battery mode). I tried recording off the UPS, powering both UFX and my laptop (Thinkpad W520), but it went only for 40 minutes or something before my laptop switches to battery mode. But I usually need longer than 2 hours for location/remote recording, so I figured much bigger UPS is necessary. And that will be expensive and too heavy to lug around. So, now I just use the CyberPower UPS, just as UPS. I think it is still possible for you, if your recording time is short, or if you can carry heavier/bigger UPS all the time. I haven't tried how long I can go with the laptop on battery mode, so it may go longer than 1 hour. I have to test. Another possibility is to hook up just UFX and use DUREC to extend the battery life, which is another thing I have to try again later.