---
product_id: 72948431
title: "First Alert BRK SMI100-AC Hardwired Smoke Detector with Battery Backup, 6-Pack"
brand: "first alert"
price: "€ 220.83"
currency: EUR
in_stock: true
reviews_count: 8
category: "First Alert"
url: https://www.desertcart.gr/products/72948431-first-alert-brk-smi100-ac-hardwired-smoke-detector-with-battery
store_origin: GR
region: Greece
---

# Battery backup for power outages Interconnect up to 18 units Easy open mounting design First Alert BRK SMI100-AC Hardwired Smoke Detector with Battery Backup, 6-Pack

**Brand:** first alert
**Price:** € 220.83
**Availability:** ✅ In Stock

## Summary

> 🔥 Stay ahead of danger with the smartest smoke alarms on the block! 🔥

## Quick Answers

- **What is this?** First Alert BRK SMI100-AC Hardwired Smoke Detector with Battery Backup, 6-Pack by first alert
- **How much does it cost?** € 220.83 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.gr](https://www.desertcart.gr/products/72948431-first-alert-brk-smi100-ac-hardwired-smoke-detector-with-battery)

## 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

- • **Smart Silence & Test:** Single button to silence nuisance alarms or test functionality, saving time and stress.
- • **Uninterrupted Safety:** 120V hardwired power with 9V battery backup ensures your home stays protected even during outages.
- • **Seamless Connectivity:** Interconnect up to 18 alarms and compatible devices for whole-home alert synchronization.
- • **Built to Last a Decade:** 10-year limited warranty with tamper-resistant locking pins for peace of mind and durability.
- • **Effortless Installation:** Open mounting design and gasket-less base make setup a breeze—perfect for busy professionals.

## Overview

The First Alert BRK SMI100-AC 6-pack hardwired smoke detectors combine reliable 120V AC power with 9V battery backup to ensure continuous protection. Featuring ionization sensors for fast flaming fire detection, these alarms interconnect up to 18 units for whole-home alerts. Designed for quick installation with tamper-resistant locking pins and a single button for silence/test functions, they offer a 10-year limited warranty, making them a trusted choice for modern home safety.

## Description

Introducing the revolutionary BRK 9120 series smoke alarms which have been redesigned from the ground up. They install faster, perform better, and are even smarter than before. All of these improvements help reduce nuisance alarms and save you time and money. BRK Electronics smoke alarms are designed to be easy to install, easy to maintain, and quality-engineered for years of virtually maintenance-free service. The 9120B AC-powered smoke alarm with battery backup includes these features: ionization sensor which helps detect fast flaming fires that consume combustible materials rapidly. 120-Volt AC inter-connectable (with maximum 18 compatible devices). the alarm can be interconnected with up to 12 other compatible smoke alarms and six compatible devices like bells, horns, repeaters and door closers. If one unit triggers an alarm, all smoke alarms in the series will sound. Power indicators show which unit in the series initiated the alarm. Latching alarm indicator which automatically identifies which unit initiated the alarm. Smart technology to reduce nuisance alarms. 9-Volt battery backup for peace of mind during power malfunction. Single test/silence button which both silences a non-threatening alarm or low battery warning and allows you to test the unit's functionality. Perfect mount system including a gasket less base for easy installation and new mounting bracket that keeps the alarm secure over a wide rotation range to allow for perfect alignment. Mounting bracket lock for tamper resistance. Dust cover to keep unit clean during construction. 10-Year limited.

Review: Works great - great value - Works great and easy to install Replaced some worn out old Kiddie models that were starting to act flaky The quality is great and bright and white Easy to install and battery backup is already installed just remove the plastic pull job
Review: Easy installation - Bought these to help a friend replace her old ones. They were easy to connect (both plugged in and hard wired). I was happy to find te batteries were included. The price was great for a pack. I’d buy them again if needed.

## Features

- 6 pack of hardwired smoke alarms, includes battery backup for power outages
- Tamper resistant locking pins, single button silence/test and loud 85Db alarm
- 120-Volt AC power with 9-volt battery backup (included) to keep alarm functioning during power outage
- Open mounting design for easy installation with side load battery compartment for quick replacement and interconnect able up to 18 units (12 smoke, 6 co/heat/relay)
- 10-Year limited
- Faster turnarounds on job sites with the easy-to-install, most-trusted alarms in home safety

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B07B4CGQLT |
| Alarm | Audible |
| Best Sellers Rank | #1,765 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #8 in Smoke Detectors & Fire Alarms |
| Brand | First Alert |
| Built-In Media | 9-volt battery (6), First Alert BRK 9120B Hardwired Smoke Alarms with Battery Backup (6), Mounting brackets with hardware (6) |
| Color | White |
| Compatible Devices | smoke alarms |
| Customer Reviews | 4.7 out of 5 stars 1,200 Reviews |
| Item Dimensions D x W x H | 2.2"D x 5.6"W x 5.6"H |
| Item Type Name | Smoke Detectors |
| Item Weight | 9.6 ounces |
| Manufacturer | First Alert |
| Mfr Part Number | 9120BFF-6 |
| Model Number | 9120B |
| Number of Items | 6 |
| Operating Humidity | 10-95% RH |
| Power Source | Battery Powered |
| Product Dimensions | 2.2"D x 5.6"W x 5.6"H |
| Product Style | Hardwired |
| Sensor Type | Ionization |
| Style | Hardwired |
| UPC | 029054019387 029054019226 |
| Unit Count | 6 Count |

## Product Details

- **Alarm:** Audible
- **Brand:** First Alert
- **Color:** White
- **Compatible Devices:** smoke alarms
- **Item Weight:** 9.6 ounces
- **Operating Humidity:** 10-95% RH
- **Power Source:** Battery Powered
- **Product Dimensions:** 2.2"D x 5.6"W x 5.6"H
- **Sensor Type:** Ionization
- **Style:** Hardwired

## Images

![First Alert BRK SMI100-AC Hardwired Smoke Detector with Battery Backup, 6-Pack - Image 1](https://m.media-amazon.com/images/I/71P8xUZFBFL.jpg)

## Questions & Answers

**Q: I have 9120b detectors in my house now. I see these are 9120bff. Do you know what the difference is and will they work?**
A: I don't see a difference that would cause a problem with them communicating with each other.  They also look the same.  Not sure if this helps, good luck

**Q: Do these have to be wired in**
A: Ours were wired in

**Q: when is the espiration date?**
A: Thank you for your question. This unit has a 10 yr warranty that starts from the date of purchase.

**Q: can you put a ten year battery in this?**
A: I don't see why you couldn't. A 9 volt battery is a 9 volt battery..

## Customer Reviews

### ⭐⭐⭐⭐⭐ Works great - great value
*by M***T on May 28, 2026*

Works great and easy to install Replaced some worn out old Kiddie models that were starting to act flaky The quality is great and bright and white Easy to install and battery backup is already installed just remove the plastic pull job

### ⭐⭐⭐⭐⭐ Easy installation
*by A***E on July 15, 2026*

Bought these to help a friend replace her old ones. They were easy to connect (both plugged in and hard wired). I was happy to find te batteries were included. The price was great for a pack. I’d buy them again if needed.

### ⭐⭐⭐⭐⭐ Easy straightforward direct replacement.
*by D***R on June 12, 2026*

great kit, easy direct replacement. Upgraded the entire house in 30 mins. Can sleep easier - until next 10 years.

## Frequently Bought Together

- First Alert BRK 9120Bff-6 Hardwired Smoke Detector with Battery Backup, 6-Pack
- BRK First Alert 9120BFF/ SMI100-AC Smoke Detector, Hardwired Alarm with Battery Backup, White, 1-Pack
- Amazon Basics 8-Pack 9V Alkaline Batteries, 5-Year Shelf Life - for Smoke/CO Detector, Electronics & Audio

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*Product available on Desertcart Greece*
*Store origin: GR*
*Last updated: 2026-07-31*