I'm attempting to replace the UPS batteries which have failed. The site will be down for a while while I do this. Hopefully all goes well.

UPS battery replacement looks like it worked, so the site should now be able to weather some thunderstorms. (There's a 45 second delay between a power outage and the generator kicking in, so the UPS is critical. The batteries had failed meaning any blip in power would take the site down.)