Updated 27 Apr 2018


Protect A13

Bottom line: This photoelectric smoke alarm is good at detecting both smouldering and flaming fires. It can be grouped wirelessly and has a voice alert, but it doesn't have a 10-year battery.

Protect A13
Consumer recommended
Avg price



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Test results

Overall score
Very good

Good points

  • Good at detecting smouldering fires.
  • Good at detecting flaming fires.
  • Can be grouped (wireless).
  • Has a carbon monoxide alarm.
  • Has voice alerts.
  • Sends alerts to a smartphone.
  • Easy to use.


  • Doesn't have a 10-year battery.

Extended review

The Nest Protect does much more than a regular smoke alarm. It performed very well in our lab test, responding quickly to fires. But so did other alarms that cost much less than the Nest’s $219 price tag. Are the extra features worth it? As well as testing it in our lab, we installed it in a home for a few weeks to trial these extra features. While installing a few Nest Protect alarms isn’t cheap, we were impressed.

Mother knows best. Nest Protect uses a human voice alarm (an English woman). The voice first warns, “please be aware, there is smoke in the hallway, the alarm may sound”, then the high-pitched alarm sounds alternately with the spoken warning “emergency, there is smoke in the hallway”. Research shows human voices (and particularly female “motherly” voices) are better at waking sleeping children than alarms. In our test, with 12 alarms going off together, the Nest warning could be heard clearly above the racket, despite it being the quietest of all alarms tested (85dB). The First Alert PRC710V we tested used an American woman’s voice alongside the high-pitched alarm, but we found the voice less clear and couldn’t hear it above other alarms in our test box.

Get connected. Like other Nest products, such as security cameras, the Protect connects through a Nest account. It needs an active connection to your home WiFi network to enable many of its features (though it still works as a smoke alarm if your network goes down). Your account is accessed through a web browser or an app. Both our home triallist and test lab connected the Protect to a Nest account using WiFi.

All for one. You can define a location for each Protect you install and link them together. Interlinked alarms, which are common in hardwired systems, are a great idea – if one sounds, they all sound. The Nest wireless connection takes it further, with all alarms not just alerting you to smoke, but where it’s located. In our lab we had three Nest alarms connected. When one was in the test chamber, the other two also alerted us to the smoke.

Home and away. An alarm also sets off an alert on your phone – more alerts to a fire can only be a good thing. You’ll also get this phone alert if you aren’t at home, so you might be able to call 111 before it’s too late.

Lighting the way. The status LED on the Nest uses a proximity sensor so it operates as a pathway light. It’s nothing a plug-in sensor night light can’t do, but it’s a neat feature for a device likely to be installed on a ceiling in a hallway and used in an emergency at night.

Regular check-ups. The Nest Protect self-tests each month, checking battery level and using an in-built microphone to run a low-volume alarm test without you being present. Status is reported through your Connect account (and the app) – much better than the dreaded “2am chirp”. When lights are turned off at night, the status light on the Protect briefly turns green to show it has self-tested and is functioning properly.

Not just smoke. The Nest Protect also detects carbon monoxide (CO). If you have a gas connection, or use an unflued gas heater (a bad idea), a CO alarm could be a lifesaver. CO is a waste product of burning gas – it’s an odourless, colourless gas that’s potentially deadly. If you don’t have a gas connection or use an unflued heater, you’ll have no use for a CO detector. We didn’t test the performance of this sensor.

The deal-breaker? Our only reservation is the Nest runs on six AA batteries. It is supplied with long-lasting Energizer Ultimate Lithium disposable batteries. The battery-powered Nest takes a different path to most alarms, which are moving to sealed long-life batteries. It doesn’t meet Residential Tenancy Act requirements (though, at $219 a pop, it’s unlikely a landlord would install these alarms).

How we test

Overall score is based on smouldering and flaming fire sensitivity.

Good” or “OK” meant the alarm sounded quickly enough to alert you to danger.
Poor” meant the alarm took significantly longer to sound.
Extreme” sensitivity meant the alarm sounded so quickly they are more likely to issue false alarms.

Ease of use (/10) includes instructions and ease of installation.

See "About our test" for more information.

Noise is measured in a quiet room 3m from the alarm.

Price is from a March 2018 price survey.

Key data

Test results

Smouldering fire sensitivity
Flaming fire sensitivity
Ease of use


Avg price
Alarm type
Noise (dBA)
Battery type
6x AA (Lithium)


Battery life (years)
Not stated
Alarm life (years)
Warranty (yrs)
Hush period (min)
Not stated
Carbon monoxide alarm
Alarms can be linked
Voice alerts

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