Hardwire Smoke Detector with 9-Volt Battery Backup

There is ZERO current draw from the battery in use as a battery backup in a smoke detector unless you have a power outage. When you replace your batteries, look at the sell by date on the package. This is basically the self discharge rate for the battery. In other words, expensive alkaline 9V batteries can be sold for up to 6 years after manufacture and still hold sufficient charge. Some even longer. I used to use lithium batteries but many of them did not last longer than high quality name brand alkaine batteries as backup power for a smoke alarm. Multiply that times 6 or 8 and you see why affordable batteries matter as backup power in smoke alarms. Achilles heel of a battery backup --AND A Big Nuisance!!! Batteries will all slowly self discharge to the point where the smoke detector measures insufficient voltage and starts beeping. This will happen at 3am on a WEEKNIGHT! (5/7 chances of that OR >70% CHANCE YOU WILL BE AWAKENED AT 3AM FROM THE CHIRP OF A DEAD SMOKE ALARM). Why 3am? that is when the house temp has cooled down and batteries performance degrades with lower temps. So if this happens to you and you don't want to wake your neighbors when you shoot your celing to silence these troublemakers, try turning up the heat and going back to sleep after the smoke alarm batteries warm up enough to shut down the chirps. I have vaulted ceilings throughout the house and my smoke alarms are ALWAYS at the peak of each celing as smoke rises. I refuse to drag a 12 foot step ladder around the house at 3am to search for the errant battery.

Hello KF, The red LED is supposed to blink every 30-45 seconds. There is no on off switch.

Not a smoker of anything but I do know that Vape Smoke isn't actually "smoke" its water vapor

Hello Ben, They are approximately 1.5" deep and 6" wide.

Sorry, no batteries. The smoke detectors work well and are easy to rewire.

hello George97220, The unit cannot be run without the battery installed as it will continue to chirp to indicate it has a bad or missing battery.

Simply pull on the yellow material tab and the battery will come out. Likewise, when replacing the battery, make sure the yellow material tab is down first in the slot for the battery with a part of it sticking up, then place the new battery down. The idea of having the yellow material tab stick up along side the battery is so when you replace THAT battery, the yellow material tab pulls up on the battery.

I purchased mine from the Home Depot online and had them delivered to the local store. It was a multi-pack (I also ordered a single unit to cover replacing all of the old ones). Of course you can have them home delivered as well.

Purchased several i12040 in 2017. Yes, each smoke detector comes with pre-installed battery located inside back of the unit. Specifications says “battery included!” as well.

Mine too, with a full alarm, not just the warning beep for low battery. I'd like to know why as well.