The First Alert SC5 Smart Smoke and Carbon Monoxide Alarm is the replacement for the Google Nest Protect Smoke Alarm – in fact, it shares most of the same attributes as the Nest Protect alarm.

The design looks very similar to, and has the same form factor as, it’s predecessor. However, there are a few key differences:

  • No path light activated at night
  • Different mounting bracket for wired and battery design
  • CR123A batteries are used instead of AA (battery powered)

Unfortunately, we don’t like the new battery choice made by First Alert – they’ve started using 6 x CR123A batteries instead of the lithium AA batteries used in the Nest Protect. While it isn’t too much of an issue – the wired version comes with a nice rechargeable battery inside – it is annoying that we have to buy and stock a different type of battery for this device.

We still recommend having at least one smart smoke alarm, or using a smart listening device, to give you alerts when the alarm goes off in your short-term rental. This ensures you are aware of any smoke or carbon monoxide-related events, either from smoking indoors or from a potential fire.

greg

First Alert SC5 Review

First Alert SC5
8 10 0 1
This is an excellent choice to use at a short-term rental to monitor the smoke & carbon monoxide at the property. It feels like a great upgrade to the original Nest Protect smoke alarm that was discontinued in March 2025, and First Alert has made some nice enhancements/improvements from the original design.
This is an excellent choice to use at a short-term rental to monitor the smoke & carbon monoxide at the property. It feels like a great upgrade to the original Nest Protect smoke alarm that was discontinued in March 2025, and First Alert has made some nice enhancements/improvements from the original design.
8/10
Total Score
  • Integrations
    6/10
    Integrates with Google Home and First Alert app only
  • Features
    9/10
    Heads up alerts & safety checks
  • Suitability for STRs
    10/10
    Great features to prevent false alarms & keep the host informed
  • Cost
    7/10
    Currently selling for $129, it is an expensive option

The Good

  • Connected to other alarms and online (for alerts)
  • Easy to set up & use
  • Provides heads up warnings
  • Integrates with Google Home

The Bad

  • Battery version uses CR123A batteries x6
  • Have to install with the First Alert app

Note: Our goal with these device reviews and recommendations is to help you get your short-term rental automated quickly, reliably and securely. We want you to use our software, so we have provided these reviews & recommendations to help you get started.

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