Winner
Price unavailable right now
Updated October 2026
Data from the official Google and X-Sense sites.
2026 verdict
Guarding a home against smoke and carbon monoxide, the Google Nest Protect (Battery) is the pick between these two alarms.
Only it detects both hazards, and it layers on occupancy, temperature, humidity, ambient-light and motion sensing, a two-year battery, a wireless interconnect that keeps working without Wi-Fi and Google Home and Home Assistant support. The X-Sense XC0M-iR Smart Carbon Monoxide Alarm with Voice Alerts is a dedicated CO alarm, so it leaves fire detection to a separate unit, and it answers with a backlit LCD showing the live CO reading, temperature and humidity, a five-year warranty and the spoken alerts both share. Buy the Google Nest Protect (Battery) for one unit that covers smoke and CO, and the X-Sense XC0M-iR Smart Carbon Monoxide Alarm with Voice Alerts if you already own smoke alarms and want a visible, connected CO monitor.
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The biggest differences
Where these two are furthest apart, and by how much.
- Warranty2.5×X-Sense XC0M-iR Smart Carbon Monoxide Alarm with Voice Alerts5 years vs 2 years
- Battery Life2×Google Nest Protect (Battery)2 years vs 1 year
| Feature | Google Nest Protect (Battery) | X-Sense XC0M-iR Smart Carbon Monoxide Alarm with Voice Alerts | Winner |
|---|---|---|---|
| Warranty | 2 years | 5 years | X-Sense XC0M-iR Smart Carbon Monoxide Alarm with Voice Alerts |
| Battery Life | 2 years | 1 year | Google Nest Protect (Battery) |
| Connectivity | 2.4 GHz WiFi, Bluetooth, Other | 2.4 GHz WiFi | Google Nest Protect (Battery) |
| Integrations | Google Home, Home Assistant | None | Google Nest Protect (Battery) |
| Screen | NO | YES | X-Sense XC0M-iR Smart Carbon Monoxide Alarm with Voice Alerts |
| Sensors | Smoke, CO, Occupancy, Temperature, Humidity, Ambient Light, Motion | CO, Temperature, Humidity | Google Nest Protect (Battery) |
| Alerts | Fire Alerts, CO Alerts, Low Battery Alerts | CO Alerts, Low Battery Alerts | Google Nest Protect (Battery) |
| Built-in Light | YES | NO | Google Nest Protect (Battery) |
| Tests Itself | YES | NO | Google Nest Protect (Battery) |
| Pathlight | YES | NO | Google Nest Protect (Battery) |
| Steam Check | YES | NO | Google Nest Protect (Battery) |
| Rating | 4.4 | 4.4 | Tie |
What the differences mean
Hazards covered
The Google Nest Protect (Battery) watches for smoke and carbon monoxide in one unit, so a single device covers both risks. The X-Sense XC0M-iR Smart Carbon Monoxide Alarm with Voice Alerts detects carbon monoxide only, which means it sits beside a separate smoke alarm rather than replacing one.
Sensors beyond the alarm
The Nest adds occupancy, temperature, humidity, ambient-light and motion sensing, while the X-Sense keeps to temperature and humidity. Those extra sensors are what drive features like the pathlight and Steam Check.
Readout on the device
The X-Sense XC0M-iR Smart Carbon Monoxide Alarm with Voice Alerts has a backlit LCD that scrolls the live CO reading, temperature and humidity and holds the peak CO level. The Google Nest Protect (Battery) has no screen, so the only place to see its readings is the Nest app.
Battery upkeep
The Google Nest Protect (Battery) runs about two years on six AA batteries, against roughly one year on a CR123A cell for the X-Sense. Both alert you before they fall silent, but the Nest asks for fewer swaps.
Smart home reach
The Google Nest Protect (Battery) works with Google Home and Home Assistant and interconnects with other Protects over its own wireless link even with Wi-Fi off. The X-Sense XC0M-iR Smart Carbon Monoxide Alarm with Voice Alerts has no documented smart home platform and does not interconnect.
Self-test and nuisance alarms
The Nest tests itself hundreds of times a day and uses a humidity reading for Steam Check, so showers and cooking are less likely to set it off. The X-Sense has neither, and self-testing is not documented.
Which one to buy if
- you want one unit to cover smoke and carbon monoxide
The Google Nest Protect (Battery) senses both hazards, so a single mount covers fire and CO.
- you already have working smoke alarms and only need to add CO protection
The X-Sense XC0M-iR Smart Carbon Monoxide Alarm with Voice Alerts is a dedicated CO alarm that sits alongside them.
- you want to read the CO level and room climate on the device
Its backlit LCD shows live CO, temperature and humidity, while the Nest has no screen.
- your home runs on Google Home or Home Assistant
The Google Nest Protect (Battery) integrates with both and links its units together.
- you want the fewest battery changes
It runs about two years on six AA cells against roughly one year on a CR123A in the X-Sense.
Winner
Price unavailable right now
- + Battery Life: 2 years
- + Connectivity: 2.4 GHz WiFi, Bluetooth, Other
- + Integrations: Google Home, Home Assistant
- - Warranty: 2 years vs 5 years
- - Screen: NO vs YES
16% OFF
£27.71
£32.99
- + Warranty: 5 years
- + Screen: YES
- - Battery Life: 1 year vs 2 years
- - Connectivity: 2.4 GHz WiFi vs 2.4 GHz WiFi, Bluetooth, Other
What owners say
Owners of both alarms single out the spoken alerts and the phone notifications: the X-Sense XC0M-iR Smart Carbon Monoxide Alarm with Voice Alerts announces the alarm and its location, and the Google Nest Protect (Battery) says which room is affected before the loud horn. Beyond that they part ways. Google Nest Protect (Battery) owners describe the early warning as real peace of mind, one catching a toaster-oven fire and another a carbon monoxide leak, and they value the monthly self-test report and the pathlight; their recurring complaints are the fixed ten-year life that starts at manufacture, the specific lithium batteries it demands and the Nest-app lock-in with no Alexa, HomeKit or Matter. X-Sense XC0M-iR owners praise a setup that takes minutes, the live CO, temperature and humidity figures on the LCD, and having stacked it beside existing X-Sense alarms; they warn that it is CO only, that it will not link with other alarms or the SBS50 base station, and that the in-app climate figures lag the device.
Frequently Asked Questions
Which is better overall: Google Nest Protect (Battery) or X-Sense XC0M-iR Smart Carbon Monoxide Alarm with Voice Alerts?
The Google Nest Protect (Battery), for covering both hazards in one unit. It detects smoke and carbon monoxide, adds occupancy, temperature, humidity, ambient-light and motion sensing, and works with Google Home and Home Assistant. The X-Sense XC0M-iR Smart Carbon Monoxide Alarm with Voice Alerts is a dedicated carbon monoxide alarm with an LCD and a longer warranty.
What is the biggest difference between the Google Nest Protect (Battery) and the X-Sense XC0M-iR Smart Carbon Monoxide Alarm with Voice Alerts?
Coverage. The Google Nest Protect (Battery) guards against smoke and carbon monoxide, while the X-Sense XC0M-iR Smart Carbon Monoxide Alarm with Voice Alerts guards against carbon monoxide only, so the X-Sense is meant to sit beside a smoke alarm rather than replace one.
Does the X-Sense XC0M-iR Smart Carbon Monoxide Alarm with Voice Alerts detect smoke?
No. It is a dedicated carbon monoxide alarm with an electrochemical CO sensor and no smoke sensor, so it needs a separate smoke alarm for fire protection.
Do these alarms work with Alexa, Apple HomeKit or Matter?
No. The Google Nest Protect (Battery) works with Google Home and Home Assistant, and the X-Sense XC0M-iR Smart Carbon Monoxide Alarm with Voice Alerts has no documented smart home platform. Neither supports Alexa, Apple HomeKit, Samsung SmartThings or Matter.
How often do the batteries need changing?
The Google Nest Protect (Battery) runs about two years on six AA batteries and the X-Sense XC0M-iR Smart Carbon Monoxide Alarm with Voice Alerts about a year on a replaceable CR123A cell. Both announce a low battery before they stop.
Who should buy the X-Sense XC0M-iR Smart Carbon Monoxide Alarm with Voice Alerts?
A home with a gas boiler, stove, fireplace or attached garage that already has smoke alarms and just needs connected carbon monoxide protection with a visible reading.
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