It's only "off the grid" if your home is already off the grid.

The battery has to get power from somewhere to charge it.

I read the specs, but I don't know enough to get it.

If you had a fully charged battery and the electricity went out, how long could you power your house?

And could you be electricity self-sufficient with a battery and your own solar/wind? Energy 24-7?

Subsequently, self sufficiency regarding wind/solar would depend on how much collection takes place and again how much you use.

To answer your questions you would have to audit what you intend to use and how much you invest in collection (how many solar panels, how many wind turbines, how much wind and sun can be harvested in your area on your property, that sort of thing)

For some context look at your monthly electric bill and see how many kWh you use
in a typical month and compare that to the 10 kWh Tesla battery.

How long is indefinite? How long does it take to charge? (How much electricity am I paying for before I go off the grid in other words?)

back through the grid. So - it all depends. I think the grid is too prone to accidents and terrorism, but so much money is made from just having the grid that it may take a while to totally be free from it - nuclear, gas, coal are affected - solar and wind and good batteries disrupt all of those. The Kochs are fighting solar, using ALEC, in as many states as they can. Ironically, they are trying to make having solar attached to the grid so expensive that people will be more likely to invest in batteries, IMO and all that.

You'd need to supply at least 50-60 amps continuous, with startup current in the range of 100-125 I would think.

5.8 amps, that's your fridge, laptop, a few other small items and several LED lamps. No heat period...only off grid if you heat with a wood stove without a blower, don't plan on using a washer or do many tasks at a time.

I want true off grid at 3500 bucks...now that'd be something to crow about.