*shrug*. My family does it. Both of them. We smoke test them occasionally too, though generally because of my mom's cooking :)
Me neither. There's practically no current draw, and in any case, virtually ever smoke detector made in the last 25 years will beep if the battery is low.
Which is why plug in / battery backup types lost favor ages ago. Batteries got better, electric service still gets wiped out in a fire.
Battery smoke detectors generally run until they're burnt up. Plenty of stories from my dad (ex NYFD) about how they'd STILL be beeping away even though the entire home's on fire. They'll run until they're melted into a pile of plastic residue.
Home fire sprinklers are eventually comming too. There's no way around it - fire sprinklers have proven time and time again to save lives, which is why they're required just about everywhere (IIRC, even so called 'fireproof' buildings in NYC must have them now)
Oh, what as the topic? Mrfact being full of it? This is news?