2-Pack First Alert SC5 Battery Smart Smoke and Carbon Monoxide Alarms

Add connected smoke and carbon monoxide protection to your home with this 2-pack of First Alert SC5 smart alarms. Model SMCO600NV combines photoelectric smoke detection, electrochemical CO sensing, voice and location alerts, wireless alarm-to-alarm interconnection, and mobile notifications through the First Alert app.

The battery-powered design requires no household electrical wiring. Each alarm operates with six 3 V CR123A lithium batteries and can integrate with compatible Google Nest Protect and First Alert/BRK alarms.

Key Features

• Two First Alert SC5 smart smoke and CO alarms

• 2-in-1 smoke and carbon monoxide detection

• Advanced Precision Detection technology

• Photoelectric smoke sensor

• Electrochemical carbon monoxide sensor

• Mobile alerts through the First Alert app

• Voice alerts identify the threat type and location

• Heads-Up advance warning

• Wireless alarm-to-alarm interconnection

• When one compatible alarm sounds, connected alarms sound

• Compatible with Google Nest Protect alarms

• Battery-powered installation with no hardwiring required

• Low-battery notifications through the connected system

• Six 3 V CR123A lithium batteries per alarm

• Mounting plates and hardware included

• 10-year limited warranty

Smart Mobile Notifications

Connect the alarms to the First Alert app to receive compatible notifications on your phone. The system can alert you when smoke or carbon monoxide is detected, helping you stay informed whether you are at home or away.

The app also provides maintenance information, including low-battery notifications. These advance alerts are designed to reduce the chance of being surprised by late-night low-battery chirps, but batteries must still be replaced when instructed.

A compatible mobile device, home network, First Alert account, and completed app setup may be required for connected features.

Smoke and Carbon Monoxide Detection

Each SC5 alarm contains:

• A photoelectric sensor for smoke detection

• An electrochemical sensor for carbon monoxide detection

First Alert’s Precision Detection technology is designed to provide earlier warning of common residential fires while helping reduce nuisance alarms.

The supplied “ionization” specification does not match the manufacturer’s listed sensor configuration for the SC5. The official specifications identify photoelectric smoke sensing and electrochemical CO detection. First Alert SC5 information

Voice and Location Alerts

Voice alerts announce the type and programmed location of the potential danger. This provides more specific information than a siren alone and may help occupants determine where the alarm originated.

The Heads-Up feature provides an advance voice warning before a full emergency alarm when applicable.

Wireless Whole-Home Interconnection

Compatible alarms can communicate wirelessly. When one interconnected alarm detects smoke or carbon monoxide, all properly connected compatible alarms sound.

This 2-pack is identified as compatible with Google Nest Protect and compatible First Alert or BRK alarms, allowing it to replace or integrate with supported systems. Resideo also describes the SC5 as compatible with and able to directly replace Google Nest Protect. Resideo SC5 compatibility information

Compatibility should be confirmed for every existing alarm before installation. Google Nest compatibility does not mean the SC5 is configured or controlled through the Nest app; First Alert identifies its own app for mobile alerts and setup.

Battery-Powered Installation

The included model is the battery-powered SMCO600NV, not the hardwired SMCO600NV-AC version.

Each alarm requires:

• Six 3 V CR123A lithium batteries

• Twelve batteries total for this 2-pack

First Alert specifies CR123A lithium batteries for the battery-powered SC5. Use only battery brands and types approved in the owner’s manual. First Alert battery guidance

Because these alarms are battery powered, they do not include an AC wiring harness, quick-connect plug, or separate backup battery pack.

Specifications

• Brand: First Alert

• Product line: SC5

• Package model: FSMCO600NVBX2

• Individual alarm model: SMCO600NV

• Product type: Smart smoke and carbon monoxide alarm

• Quantity: Two alarms

• Smoke sensor: Photoelectric

• CO sensor: Electrochemical

• Detection technology: Precision Detection

• Smart notifications: First Alert app

• Voice alerts: Threat type and location

• Interconnection: Wireless with compatible alarms

• Google Nest Protect compatibility: Yes

• Power source: Battery

• Battery type: 3 V CR123A lithium

• Batteries required per alarm: Six

• Total batteries for 2-pack: Twelve

• Batteries included: Yes

• Dimensions per alarm: 5.75" W × 5.75" D × 1.6" H

• Listed package weight: 1 lb.

• Warranty: 10-year limited warranty

• Condition: New

What’s Included

• Two First Alert SC5 battery-powered smart smoke and CO alarms

• Two mounting plates

• Mounting hardware

• Twelve 3 V CR123A lithium batteries—six per alarm

• Setup and owner’s documentation

A wiring harness and hardwired quick-connect plugs are not included because this package contains the battery-powered version.

Ideal For

• Replacing compatible Google Nest Protect alarms

• Adding First Alert app notifications

• Bedrooms and nearby hallways

• Living areas

• Multiple-floor homes

• Homes without hardwired alarm connections

• Expanding a compatible wireless alarm network

• Areas requiring both smoke and CO detection

Alarm quantity and placement must follow the owner’s manual and applicable local requirements.

Why It Stands Out

The SC5 combines smoke and CO detection with app notifications, voice warnings, and compatible wireless interconnection. If one connected alarm detects danger, all compatible interconnected alarms sound, while the First Alert app can provide notifications to a linked phone.

Its battery-powered construction also makes installation more flexible than a hardwired alarm, while compatibility with Google Nest Protect provides an upgrade path for supported existing systems.

Installation and Safety

• Read the owner’s manual before installation.

• Confirm that this battery-powered model is suitable for your home and local code requirements.

• Install alarms only in approved wall or ceiling locations.

• Insert all six approved CR123A batteries into each alarm.

• Download and configure the First Alert app for connected features.

• Program the correct location for each alarm.

• Pair all compatible alarms according to the manufacturer’s instructions.

• Test each alarm immediately after installation.

• Confirm that all interconnected alarms sound during network testing.

• Test the alarms regularly as directed in the manual.

• Replace batteries when instructed by the alarm or app.

• Never remove batteries merely to silence an active warning.

• Do not paint, cover, or obstruct the alarms.

• Replace the alarm when it reaches the end of its rated service life.

• If a smoke or CO warning activates, follow your emergency plan and contact emergency services.

• Never ignore a carbon monoxide warning.

• Smart notifications depend on proper setup, connectivity, and service availability; the alarm’s local audible warning remains the primary emergency alert.

Warranty and Support

The SC5 includes a 10-year limited warranty. Complete terms, limitations, and replacement procedures are provided in the owner’s manual and through First Alert.

First Alert customer service: 1-800-323-9005

Hours:

• Monday–Friday: 9:00 a.m.–8:00 p.m. Central Time

• Saturday–Sunday: 9:00 a.m.–5:30 p.m. Central Time

Frequently Asked Questions

How many alarms are included?

This package includes two First Alert SC5 battery-powered smart smoke and CO alarms.

Is this the battery or hardwired version?

It is the battery-powered SMCO600NV version. It does not require a 120 V AC hardwired connection.

How many batteries does each alarm use?

Each alarm uses six 3 V CR123A lithium batteries. Twelve batteries are included for the two alarms.

What types of hazards does it detect?

Each alarm detects smoke using a photoelectric sensor and carbon monoxide using an electrochemical sensor.

Does it send alerts to a phone?

Yes. After compatible setup, the First Alert app can send smoke, CO, maintenance, and low-battery notifications.

Is it compatible with Google Nest Protect?

Yes. First Alert identifies the SC5 as compatible with Google Nest Protect alarms. Confirm the setup and replacement requirements for your existing system before installation.

Does it use the Google Nest app?

The supplied information identifies the First Alert app for mobile alerts. Nest app control is not specified.

Do the two alarms interconnect?

Yes. Properly configured compatible alarms can interconnect wirelessly so that when one sounds, all connected alarms sound.

Does it have voice alerts?

Yes. Voice alerts identify the type and programmed location of the potential danger.

Does it use an ionization smoke sensor?

No. The manufacturer lists a photoelectric smoke sensor and an electrochemical carbon monoxide sensor.

Will it completely eliminate low-battery chirps?

The connected system can provide advance low-battery notifications, helping you replace batteries before chirping begins. It does not eliminate the need to respond to battery or maintenance warnings.

Is professional installation required?

No electrical hardwiring is required for this battery model. However, installation and placement must follow the owner’s manual and all applicable local fire and building requirements.