First Alert Hardwired Smoke Alarm SMI105-AC
- Hardwired with 10-year battery backup
- Interconnects with compatible alarms
- Ionization sensor, Precision Detection
- Alarm indicator shows which unit tripped
- Easy Adapter Plug included
- End-of-life warning
Updated 3 days ago · Based on the Amazon listing and published specifications, not hands-on testing.
A hardwired smoke alarm with a long-life backup battery that links to other compatible alarms. It detects smoke only, so pair it with a CO alarm.
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ASIN: B0CJMPZ65QModel: SMI105-AC
Overview
A homeowner replacing old hardwired alarms gets a unit that runs on house power, stays on its backup battery in outages, and links to compatible alarms. When one sounds, all sound, and an indicator shows which alarm started it.
Interconnect spreads the warning through the whole house, which matters in multi-floor homes. It senses smoke only, with no carbon monoxide detection.
Who it's for
Multi-floor homes with existing alarm wiring get linked warnings and long battery backup. Rooms without wiring need a sealed battery alarm instead.
Pros and cons
- Interconnect sounds every linked alarm
- Battery backup in outages
- Indicator shows the origin unit
- Adapter plug for existing wiring
- Smoke only, no CO
- Needs hardwired circuit
- Ionization sensor type
- Warranty not listed
Performance notes
Interconnect wiring carries the alarm signal to every linked unit, so a fire in the basement sounds upstairs too. Ionization sensing reacts quickly to fast-flaming fires, and Precision Detection aims to cut cooking alarms. The backup battery holds protection through power cuts.
Specifications
| Brand | First Alert |
|---|---|
| Model | SMI105-AC |
| Dimensions & fit | |
| Item Dimensions D X W X H | 5.6"D x 5.6"W x 2"H |
| Item Weight | 11.2 ounces |
| Power & efficiency | |
| Power Source | Corded Electric |
| Construction & materials | |
| Color | White |
| Included components | |
| Unit Count | 1 Count |
| Other details | |
| BuiltIn Media | Easy Adapter Plug |
| Item Highlight | SMI105-AC |
| Item Type Name | Smoke Alarm |
| Operating Humidity | 10-95% RH |
| Product Style | Precision Detection |
| Sensor Type | Ionization |
Frequently asked questions
How do I install the First Alert SMI105-AC?
It is a hardwired alarm with an Easy Adapter Plug included. Turn off power at the breaker and follow the instructions, or hire an electrician.
Does the First Alert SMI105-AC work in a power outage?
Yes. The 10-year battery backup provides continuous protection during outages.
Does the First Alert SMI105-AC detect carbon monoxide?
No. It is a smoke alarm only.
Will all my alarms sound when the First Alert SMI105-AC goes off?
Compatible interconnected alarms will all sound, and the indicator shows which unit started it.