---
product_id: 609937867
title: "SMI100-AC, Hardwire Interconnect Smoke Alarm with Battery Backup, 1-Pack"
brand: "first alert"
price: "€ 52.73"
currency: EUR
in_stock: true
reviews_count: 13
category: "First Alert"
url: https://www.desertcart.nl/products/609937867-smi100-ac-hardwire-interconnect-smoke-alarm-with-battery-backup-1
store_origin: NL
region: Netherlands
---

# Hardwired with battery backup Interconnects all alarms instantly Quick Connect Plug for easy install SMI100-AC, Hardwire Interconnect Smoke Alarm with Battery Backup, 1-Pack

**Brand:** first alert
**Price:** € 52.73
**Availability:** ✅ In Stock

## Summary

> 🔥 Stay ahead of danger with smart, seamless protection ⚡

## Quick Answers

- **What is this?** SMI100-AC, Hardwire Interconnect Smoke Alarm with Battery Backup, 1-Pack by first alert
- **How much does it cost?** € 52.73 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.nl](https://www.desertcart.nl/products/609937867-smi100-ac-hardwire-interconnect-smoke-alarm-with-battery-backup-1)

## 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

- • **Power Outage Proof:** Battery backup keeps protection 24/7, no matter what
- • **Trusted & Top-Ranked:** #2 in Smoke Detectors with 4.6-star reliability
- • **Effortless Installation:** Quick Connect Plug means no rewiring headaches
- • **Precision Detection Tech:** Reduces false alarms, so your peace stays intact
- • **Whole-Home Early Warning:** One alarm triggers all—safety that speaks as one

## Overview

The First Alert SMI100-AC is a hardwired smoke alarm featuring advanced Precision Detection technology to minimize nuisance alerts while providing early fire warnings. It interconnects with compatible alarms for whole-home safety, includes a battery backup for continuous protection during outages, and installs easily with a Quick Connect Plug—making it a top-rated, reliable choice for modern homes.

## Description

The First Alert SMI100-AC Hardwire Interconnect Smoke Alarm with Battery Backup meets new industry standards utilizing First Alert's Precision Detection advance sensing technology. This hardwire smoke alarm is easy to install and replace existing alarms with no need to rewire. Plus interconnect compatible alarms to create a whole home alarm system to help provide an early warning.

Review: Great price , quick install, and great product! - They look and work great the lights aren’t bright so sleeping isn’t a problem. Installation quick and easy for my Contractor. No parts were missing although box was a litte dented which I am ok with. Great price!!! Thanks desertcart.
Review: Best smoke detector! - Ordered this set to replace all my upstairs smoke detectors! They were pretty much newer versions of what I had, very simple install all function well as well! Great value and great quality from a trusted brand!

## Features

- First Alert's 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.
- Through early warning interconnect, when one alarm sounds, all compatible alarms will sound
- Battery backup provides continuous protection during power outages
- Alarm indicator visually identifies the unit that initiated the alarm
- Quick Connect Plug included allows for easy installation with no need to rewire

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B0CJMN3443 |
| Alarm | Smoke Alarm |
| Batteries | 1 9V batteries required. (included) |
| Batteries Included? | Yes |
| Batteries Required? | Yes |
| Battery Cell Type | Alkaline |
| Best Sellers Rank | #116 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #2 in Smoke Detectors & Fire Alarms |
| Brand | First Alert |
| Color | White |
| Customer Reviews | 4.6 4.6 out of 5 stars (6,762) |
| Date First Available | September 22, 2023 |
| Global Trade Identification Number | 10029054022469 |
| Included Components | Easy Adapter Plug, 9V Alkaline Battery |
| Item Package Quantity | 1 |
| Item Weight | 9.6 ounces |
| Item model number | SMI100-AC |
| Manufacturer | Resideo |
| Number of Items | 1 |
| Part Number | SMI100-AC |
| Pattern | SMI100-AC |
| Power Source | Battery Powered |
| Product Dimensions | 5.6"D x 5.6"W x 1"H |
| Sensor Type | Ionization |
| Size | 1-Pack |
| Style | Precision Detection |
| UPC | 029054022462 |

## Product Details

- **Alarm:** Smoke Alarm
- **Brand:** First Alert
- **Color:** White
- **Global Trade Identification Number:** 10029054022469
- **Item Weight:** 9.6 ounces
- **Number of Items:** 1
- **Power Source:** Battery Powered
- **Product Dimensions:** 5.6"D x 5.6"W x 1"H
- **Sensor Type:** Ionization
- **Style:** Precision Detection

## Images

![SMI100-AC, Hardwire Interconnect Smoke Alarm with Battery Backup, 1-Pack - Image 1](https://m.media-amazon.com/images/I/61zYUADll+L.jpg)

## Customer Reviews

### ⭐⭐⭐⭐⭐ Great price , quick install, and great product!
*by B***N on January 26, 2026*

They look and work great the lights aren’t bright so sleeping isn’t a problem. Installation quick and easy for my Contractor. No parts were missing although box was a litte dented which I am ok with. Great price!!! Thanks Amazon.

### ⭐⭐⭐⭐⭐ Best smoke detector!
*by P***T on January 8, 2026*

Ordered this set to replace all my upstairs smoke detectors! They were pretty much newer versions of what I had, very simple install all function well as well! Great value and great quality from a trusted brand!

### ⭐⭐⭐⭐⭐ INCREDIBLE PRODUCT!!!!!!!!!!!
*by P***T on January 28, 2026*

Check this out!!! I ordered 3 of these to replace my 25 year old First Alert BRK 4120B I used when I build my home. To my absolute amazement this recommended replacement replaced exactly the ones I had that were 25 years old!!! The only issue was the original base was slightly different so I just put the new base on, plugged it in, and twisted it on. Took exactly 10 minutes to replace all three 25 year old smoke detectors. Hats off to this company for making replacing these so easy. I thought this was going to be nightmare but so incredibly easy. Would recommend this to anyone trying to replace their old smoke detectors. Each unit also came with a battery backup. GREAT PRODUCT.....GREAT DESIGN !!!!!!!!!!!!!!!!!!!

## Frequently Bought Together

- First Alert SMI100-AC, 9120B Replacement Hardwire Interconnect Smoke Alarm with Battery Backup, 1-Pack
- First Alert SMICO100-AC Interconnect Hardwire Combination Smoke & Carbon Monoxide Alarm with Battery Backup, 1-Pack
- First Alert 9120B Smoke Detector, Hardwired Alarm with Battery Backup, 6-Pack

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*Product available on Desertcart Netherlands*
*Store origin: NL*
*Last updated: 2026-03-03*