Correct. The Cyberpower UPS I have has an external battery pack attached. The battery pack has its own charger (you can have up to 10 of them on one UPS, and the UPS by itself isn't capable of charging that much battery in any reasonable period of time).So 2 circuits , but one UPS ? Not sure what "battery charger for the extended battery pack" would be as stand alone devices, but basically no redundancy of UPS failure , right ? So if on the first circuit the UPS goes down, everything goes down, right ?
The house only has a single feed from the local utility, so I'm not too worried about it. I've got ~2hrs. to get power back, or to transfer to generator (which, today, involves an external generator and cord... but in the future will be automatic, with a generator sized to run the whole house).