No, I haven't done the math. End of the day, get the most capacity you have the budget and space for. If you're looking to add batteries to a ups, I would only use a high quality unit with active cooling(built in fans). Such as
this unit, which I use. I found mine used for $100 with bad batteries. The smaller cheap ones will not last very long being ran hours on end like that. I only need mine to last until a hurricane passes then I get out the generator. So I run the entire tank and tv/ lights. If I reduced to just a return pump it would last days. But I don't need that, some may..