First Alert SMI105-AC, Interconnect Hardwire Smoke Alarm with 10-Year Battery Backup, 1-Pack
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Availability:
In Stock.
Arrives
Tuesday, Jun 23
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Style: Precision Detection
Pattern Name: SMI105-AC
Size: 1-Pack
Features
- First Alerts Precision Detection advanced sensing technology complies with new industry standards to reduce cooking nuisance alarms and provides early warning in the event of a home fire emergency.
- 10-Year battery backup provides continuous protection during power outages
- Through early warning interconnect, when one alarm sounds, all compatible
- Alarm indicator visually identifies the unit that initiated the alarm
- End-of-life warning lets you know when its time to replace the alarm
Description
The First Alert SMI105-AC Interconnect Hardwire Smoke Alarm with 10-Year Battery Backup uses First Alert's Precision Detection advanced sensing technology and meets new industry standards. Interconnect multiple alarms together to help provide an early warning throughout your whole home and have peace of mind knowing the 10-year battery backup provides continuous protection in the event of a power outage.
Brand: First Alert
Style: Precision Detection
Power Source: Corded Electric
Color: White
Product Dimensions: 5.6"D x 5.6"W x 2"H
Item Weight: 0.7 Pounds
Alarm: Smoke
Operating Humidity: 10-95% RH
Sensor Type: Ionization
Unit Count: 1.0 Count
Power Source: Corded Electric
Alarm: Smoke
Sensor Type: Ionization
Operating Humidity: 10-95% RH
Product Style: Precision Detection
Color: White
Item Dimensions D x W x H: 5.6"D x 5.6"W x 2"H
Item Weight: 0.7 Pounds
Brand: First Alert
Model Number: SMI105-AC
Number of Items: 1
Manufacturer: Resideo
UPC: 029054022615
Mfr Part Number: SMI105-AC
Unit Count: 1.0 Count
Item Type Name: Smoke Alarm
Built-In Media: Easy Adapter Plug
Frequently asked questions
If you place your order now, the estimated arrival date for this product is:
Tuesday, Jun 23
Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.
To initiate a return, please visit our Returns Center.
View our full returns policy here.
To initiate a return, please visit our Returns Center.
View our full returns policy here.
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Similar Products
Top Amazon Reviews
Style: Precision Detection
Pattern Name: SMI105-AC
Size: 1-Pack
Easy to install and gives great peace of mind. I love the 10-year backup battery because no more annoying late-night chirping from low batteries. The interconnect feature is great too since all alarms sound together for extra safety. Solid quality and definitely worth upgrading older smoke detectors.
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Reviewed in the United States on May 23, 2026 by MoD
Style: Precision Detection
Pattern Name: SMI105-AC
Size: 1-Pack
My old Kidde detectors gave consistent false alarms over the years, usually at around 3am or so. Not sure what that is all about. But I decided to change them out with a different brand and hope for a better experience. These required rewiring the included pigtails for each detector, mounting plates used the existing screws for mounting. The 10-year battery life is perfect, as smoke detectors are recommended to be replaced at least every10 years. Interesting note... they have a green LED indicator light that illuminates the backside of each unit. Not a bight, in your face type of light, just a subtle glow. Five units installed, all work perfect.
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Reviewed in the United States on May 3, 2026 by Brett A.
Style: Precision Detection
Pattern Name: SMI105-AC
Size: 3-Pack
Built in long life battery means no need to replace and no need to try to shut up annoying chirping of dying battery at inconvenient hours. Unit fits plug in connector and bracket of older units. Meaning replacement installation is simple: twist off old one, pull electrical connector off old one, plug connector into same spot on replacement and twist on new one into original wall/ceiling bracket. Then pull out plastic battery tab to connect battery and activate unit. Multipacks are economical way to replace all units at once. Theoretically, units have a ten year life. Replacing all units at same time is easier than tracking life of individual units and ensures all are within operational window.
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Reviewed in the United States on February 25, 2026 by Paul Z
Style: Precision Detection
Pattern Name: SMI105-AC
Size: 1-Pack
Screws to mount were missing but otherwise I'm very happy with it. Easy install once I found my own screws. Really like the 10 year battery as I am getting to old to climb up on a ladder to change a battery
Reviewed in the United States on June 6, 2026 by Amazon Customer
Style: Precision Detection
Pattern Name: SMI105-AC
Size: 1-Pack
Bought this smoke detector because, you know, fire safety is important… Apparently not important enough for me to install it in under 90 days. But hey — I had other things to do. Like reorganize the garage. Twice. And stare at it in the box on the kitchen counter like it was going to mount itself. Meanwhile, my wife spent three months walking past it like she was in a house made of dry hay and open flames. Every time the oven turned on, I got the look. You know the one — the “If the toaster sparks, we’re done” look. ⸻ 🔥 Smoke Detector Functionality Once I finally summoned the courage (and a step stool), this thing installed easily and worked like a champ. Tested it with the “toast test” and yep — she’s got lungs. Loud enough to wake the neighbors, the pets, and possibly the dead. I feel safer already. So does my marriage. ⸻ 💵 Value for Money Excellent. A small price to pay for not living in a potential fireball and regaining my wife’s trust. Honestly, I should’ve paid more just for the emotional damage I caused by procrastinating. ⸻ 🧰 Quality & Build Solid construction. Doesn’t feel cheap or flimsy. You can tell it’s built to detect danger, not just hang out on the ceiling for decoration. ⸻ 🔄 Ease of Replacement Swapping it in for the old detector was fast and painless. If only me actually doing it had been that easy. Seriously, it took longer to unwrap it than to install it — once I finally picked up a screwdriver. ⸻ 🧯 Final Thoughts: • Yes, it works great. • Yes, it’s loud, reliable, and makes us feel safe. • No, I can’t explain why it took me a whole fiscal quarter to install it. Wife’s happy. House didn’t burn down. Marriage survived. 10/10 would delay installation again (kidding, honey).
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Reviewed in the United States on August 23, 2025 by Anthony S
Style: Precision Detection
Pattern Name: SMI105-AC
Size: 1-Pack
Still working very well
Reviewed in the United States on June 6, 2026 by Jim O.
Style: Precision Detection
Pattern Name: SMI105-AC
Size: 3-Pack
These smoke detectors are easy to install and are a peace of mind knowing they can alert me and my family in case of emergency
Reviewed in the United States on May 30, 2026 by Jim Pyle
Style: Precision Detection
Pattern Name: SMI105-AC
Size: 1-Pack
Absolute fail of a product. I guess having a battery that simply fits into the alarm tray and then you slide the tray into the alarm would be too simple. Nope, someone had to over-design this, and now the alarm comes with a battery tray that is LOCKED! but you can't open it. It says refer to instruction on how to do this, but the instructions (that's a very loose term btw) don't specify how to open the damn tray. It just says use a tool to cut the pin...what pin? where is the pin? there is nothing there. So you have an alarm that you cannot activate because the clear tape that you should pull out to activate the battery won't pull out, and the battery tray won't open. I guess its suppose to be a safty device that no one needed, to stop tampering I suppose. But why have the default state it's shipped as locked?????......update: So after having spent a conciderable amount of time online and finding many others tearing their hair out with the same issue, i finally found wher ethe pin is. It's actually hidden. i kid you not. It's under the slabel sticker that covers the entire underneath of the alarm. Loads of tiny information that mostly doesn't concern anyone is printed on this label. and in what's probably the smallest possible font size is a little note telling you to cut a small part of the label away/scrape it off with a knife (because it wont just peel) and underneath the label, hidden away, is a TINY pin. No indication what it is or how to remove it. It's white plastic, so is the entire alarm. It's almost impossible to distinguish it from the alwarm housing. I took a jewelry screw driver I was fortunate enough to have. There is no way to unscrew it, you just have to force it out and hope thats what you are supposed to do.......I nominate this for 'Design fail of the year'
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Reviewed in the United States on May 26, 2025 by Bolan