10/15/2026
The honest trade-off, since nobody puts it on a spec sheet.
A battery is silent, needs no fuel delivery, and can live inside a garage, which a combustion unit cannot. What it has is a finite amount of stored energy, so the design conversation is about which circuits matter to you: the furnace, the fridge, a few outlets and the internet will run a long time. The whole house at once will not.
Sort that out first and the sizing answers itself.
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