---
product_id: 609937868
title: "First Alert SMI105-AC, Interconnect Hardwire Smoke Alarm with 10-Year Battery Backup, 1-Pack"
brand: "first alert"
price: "$114"
currency: NZD
in_stock: true
reviews_count: 8
category: "First Alert"
url: https://www.desertcart.nz/products/609937868-first-alert-smi105-ac-interconnect-hardwire-smoke-alarm-with-10
store_origin: NZ
region: New Zealand
---

# Interconnects multiple alarms 10-year battery backup Precision Detection tech First Alert SMI105-AC, Interconnect Hardwire Smoke Alarm with 10-Year Battery Backup, 1-Pack

**Brand:** first alert
**Price:** $114
**Availability:** ✅ In Stock

## Summary

> 🔥 Stay ahead of danger with smart, silent protection that never quits!

## Quick Answers

- **What is this?** First Alert SMI105-AC, Interconnect Hardwire Smoke Alarm with 10-Year Battery Backup, 1-Pack by first alert
- **How much does it cost?** $114 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.nz](https://www.desertcart.nz/products/609937868-first-alert-smi105-ac-interconnect-hardwire-smoke-alarm-with-10)

## Best For

- first alert enthusiasts

## Why This Product

- Trusted first alert brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **End-of-Life Alert:** Stay ahead of safety with timely notifications when it’s time to replace your smoke alarm.
- • **Decade-Long Defense:** 10-year lithium battery backup ensures uninterrupted protection, even during power outages.
- • **Visual Alarm Indicator:** Quickly identify which unit triggered the alert with a clear, built-in alarm indicator.
- • **Smart Home Safety Network:** Interconnect multiple alarms so when one detects smoke, all sound—early warning for your entire home.
- • **Precision Detection Technology:** Advanced sensing reduces false alarms from cooking, giving you peace of mind without the nuisance.

## Overview

The First Alert SMI105-AC is a hardwired smoke alarm featuring advanced Precision Detection technology that minimizes false alarms and provides early fire warnings. It includes a 10-year lithium battery backup for continuous protection during outages and can interconnect with other compatible alarms to alert your entire home simultaneously. With visual alarm indicators and end-of-life warnings, it combines reliability, convenience, and long-term safety in one sleek, easy-to-install unit.

## 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.

Review: Nice units and look great - Easy to install. Make power is off before you begin. Remove old detector but leave the screws annd use those to attach the new one to the electrical box. If you need to use the included adapter go ahead and connect the white to white, black to black and orange to red. Then just connect the adapter to the new detector. Be sure to remove the clear plastic strip to activate the battery. NOTE. You don’t need to connect the orange to red if the detector is not going to be connected to communicate with other detectors.
Review: Works Great — Once You Actually Install It (According to My Wife, 3 Months Late) - 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).

## 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 it’s time to replace the alarm

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B0CJMPZ65Q |
| Alarm | Smoke |
| Batteries | 1 9V batteries required. (included) |
| Batteries Included? | Yes |
| Batteries Required? | Yes |
| Battery Cell Type | Lithium |
| Best Sellers Rank | #3,525 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #15 in Smoke Detectors & Fire Alarms |
| Brand | First Alert |
| Color | White |
| Customer Reviews | 4.5 4.5 out of 5 stars (1,996) |
| Date First Available | September 22, 2023 |
| Included Components | Easy Adapter Plug |
| Item Package Quantity | 1 |
| Item Weight | 11.2 ounces |
| Item model number | SMI105-AC |
| Manufacturer | Resideo |
| Number of Items | 1 |
| Operating Humidity | 10-95% RH |
| Part Number | SMI105-AC |
| Pattern | SMI105-AC |
| Power Source | Battery Powered |
| Product Dimensions | 5.6"D x 5.6"W x 2"H |
| Sensor Type | Ionization |
| Size | 1-Pack |
| Style | Precision Detection |
| UPC | 029054022615 |

## Product Details

- **Alarm:** Smoke
- **Brand:** First Alert
- **Color:** White
- **Item Weight:** 0.7 Pounds
- **Number of Items:** 1
- **Operating Humidity:** 10-95% RH
- **Power Source:** Battery Powered
- **Product Dimensions:** 5.6"D x 5.6"W x 2"H
- **Sensor Type:** Ionization
- **Style:** Precision Detection

## Images

![First Alert SMI105-AC, Interconnect Hardwire Smoke Alarm with 10-Year Battery Backup, 1-Pack - Image 1](https://m.media-amazon.com/images/I/71yErRIjxzL.jpg)

## Available Options

This product comes in different **Pattern, Size, Style** options.

## Customer Reviews

### ⭐⭐⭐⭐⭐ Nice units and look great
*by J***N on January 17, 2026*

Easy to install. Make power is off before you begin. Remove old detector but leave the screws annd use those to attach the new one to the electrical box. If you need to use the included adapter go ahead and connect the white to white, black to black and orange to red. Then just connect the adapter to the new detector. Be sure to remove the clear plastic strip to activate the battery. NOTE. You don’t need to connect the orange to red if the detector is not going to be connected to communicate with other detectors.

### ⭐⭐⭐⭐⭐ Works Great — Once You Actually Install It (According to My Wife, 3 Months Late)
*by A***S on August 23, 2025*

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).

### ⭐⭐⭐⭐⭐ Easy to install. Peace of mind
*by A***1 on January 5, 2026*

Easy to install. Working nicely one year later

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*Product available on Desertcart New Zealand*
*Store origin: NZ*
*Last updated: 2026-02-28*