Had a power outage early this AM during overnight charging, and I need to leave before the power came back on. I had enough accumulated range by that point, but I noticed that I couldn't unplug the charger cable from the charge port because the button on the UMC handle wouldn't release the electrical interlock (the UMC evidently needs AC mains power for this function to work). Pressing the "open charge port" icon on the touchscreen had no effect. So I unplugged the UMC from my 220V outlet and used an extension cord to temporarily plug it into an AC outlet on my computer's UPS (which was running on its gel cell of course). The UMC displayed a red error indication because the UPS inverter output was not suitable for charging, but all I needed was temporary availability of 110V to unlock the charging port, which worked fine and I was on my way. Just something to be aware of, this situation doesn't occur very often. Didn't see this topic covered in my forum searches, but apologize if I missed it.