First Alert SC5 Smart Smoke and CO Alarm SMCO600NV-AC
- Smoke and CO in one alarm, hardwired with battery backup
- 3V lithium battery pack for power outages
- Google Nest Protect compatible, phone alerts via First Alert app
- Voice alerts name the danger type and location
- Quick Connect Plug for installation and replacement without rewiring
- 5.75 x 5.75 x 1.6 inches, 16 oz
Last refreshed Sep 8, 2026 · Based on the Amazon listing and published specifications, not hands-on testing.
A sound choice for homes that already have hardwired alarms and want phone alerts plus Nest Protect compatibility. It needs an existing alarm circuit, so homes without one should look at a battery model.
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ASIN: B0DS2VG4P1Model: SC5Category: Smoke Detectors & Fire Alarms
Overview
First Alert built this hardwired smart alarm to watch for both smoke and carbon monoxide from one unit running on household power. A plug connector joins it to the house wiring, a lithium pack backs it up in an outage, and the First Alert app pushes alerts to a phone.
Phone alerts and spoken warnings that name the danger and its location are the reason to choose it. Interconnect means one alarm sounding sets off every compatible alarm in the home. Sensor technology, alarm volume and service life are not spelled out in the listing.
Who it's for
Houses already wired for smoke alarms, especially ones running Nest Protect units, are the target. Without an existing alarm circuit, a battery powered alarm is the easier route.
Pros and cons
- Detects smoke and carbon monoxide in one unit
- Phone alerts through the First Alert app
- Works alongside Google Nest Protect alarms
- Voice alerts state danger type and location
- Requires an existing hardwired alarm circuit
- Sensor type and decibel level not listed
- Phone alerts depend on the app
Performance notes
Detection runs on First Alert's Precision Detection Technology, which is meant to separate real hazards from nuisance triggers and give an early warning. Household power runs the alarm day to day, and the lithium pack takes over when the power drops. Interconnect spreads the warning to every compatible alarm, and the app relays it to a phone when nobody is home.
Specifications
| Brand | First Alert |
|---|---|
| Model | SC5 |
Frequently asked questions
What does the date printed on the First Alert SMCO600NV-AC mean?
It is the manufacture date, which shows when the alarm was produced.
Does the First Alert SMCO600NV-AC work with Google Nest Protect?
Yes. The listing states it is compatible with Google's Nest Protect alarm, and when one compatible alarm sounds, all of them sound.
Can I install the First Alert SC5 hardwired alarm without new wiring?
Its Quick Connect Plug is made for installation and replacement with no need to rewire, but it is a hardwired unit and needs an existing alarm connection.