When I lived off the grid back in the '70s we used to use a car battery to power our TV. Just have two, run the car off one, and swap them out when the house battery gets low, it will recharge in the car. Of course in those days we had an old truck that you could park on a hill and bump start if the battery got too low. That's about all we used electricity for. Lights were kerosene.
If you're trying to run a regular, modern household off of it, I'd think you'd be better off with a diesel generator, or possibly a propane generator.