Yes, the lead-acid battery is used to start the generator, but it's a gasoline 27 hp., 2 cyl. Kohler engine. No load battery voltage is 12.7 volts, cranking 12.0 volts. The battery is severely oversized with respect to the engine for normal applications. Was thinking the battery is there, and kept charged, why not use it as the UPS, and eliminate one more piece of equipment to maintain (a separate UPS), but maybe that's a better way to go, a UPS meant for a PC could easily bridge the power outages and aren't that expensive. I was thinking an electronic relay circuit controlled by the 120 volt supply would switch quick enough to keep the PLC from resetting .