120v smoke detector w/lithium bat?

[John]

I see there are battery powered smoke detectors with a ten year lithium battery. However, I don't see any hard wired smoke detectors with a ten year lithium battery for backup. I currently have those in my house but they are ten years old and I need to replace them (the whole smoke detectors). Even on the website (Firex) I see only regular 9v backup battery models . If I have to, I'll buy those, but am wondering if anyone knows of a source for what I'm looking for. The ones I have are Firex model G-4.

[toller]

Maybe a lithium 9v battery?

[Pop]

I don't know of any sources, but ... I bought three of those suckers at various times and not a ONE of them outlasted the regular 9V battery operated ones by more than a few MONTHS!! Never found the receipt, so I was out all that extra money invested in the battery (cost added to the detector for the battery).

YMMV, but I'll never touch another one.

Pop