Air con???  Con Air??

Not for very long at one time, with a 12 V automotive battery of
reasonable size.  Air conditioner pumps are typically belt-driven
rather than electrical accessories because they do a lot of work -- in
the old days the rule of thumb was 10-15 horsepower, though more
efficient compressors   have dropped that into the single digit range.
 Throw in some inefficiencies and you've got a whole lotta amps at 12
V dc.

I think hybrids used to generally use a belt-driven compressor but now
some of the more advanced ones use a husky inverter and an electric
compressor.

Note here that user expectations of performance play a role too --
automobile A/C systems have MUCH more cooling capacity, compared to the
size of the "room," than you'd find in a house.  There's a lot of
"greenhouse effect" with all those windows, and people then want the
thing cooled down in a hurry.

Cheers,
--Joe

A/C systems require gobs of power. The battery technology of today is
inadequate for that task...

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