Winner
7% OFF
£65.00
£69.74
Updated October 2026
Data from the official Shelly and X-Sense sites.
2026 verdict
A smoke detector against a carbon monoxide alarm, and the Shelly Plus Smoke Alarm takes this matchup on the strength of its integrations and its battery life.
It pairs straight to Wi-Fi with no hub, joins Google Home, Samsung SmartThings and Home Assistant, supports MQTT and automations, has a built-in light, and runs about five years on a CR123A cell. The X-Sense XC0M-iR Smart Carbon Monoxide Alarm with Voice Alerts answers with what the Shelly cannot do: it senses carbon monoxide, temperature and humidity, speaks its alerts, shows an LCD with the CO peak, and carries a five-year warranty. The two guard different hazards, so choose the Shelly Plus Smoke Alarm for fire coverage that drives a smart home, and the X-Sense XC0M-iR Smart Carbon Monoxide Alarm with Voice Alerts for CO and indoor climate.
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The biggest differences
Where these two are furthest apart, and by how much.
- Battery Life5×Shelly Plus Smoke Alarm5 years vs 1 year
- Warranty+67%X-Sense XC0M-iR Smart Carbon Monoxide Alarm with Voice Alerts5 years vs 3 years
| Feature | Shelly Plus Smoke Alarm | X-Sense XC0M-iR Smart Carbon Monoxide Alarm with Voice Alerts | Winner |
|---|---|---|---|
| Price | £65.00 | £27.71 | X-Sense XC0M-iR Smart Carbon Monoxide Alarm with Voice Alerts |
| Warranty | 3 years | 5 years | X-Sense XC0M-iR Smart Carbon Monoxide Alarm with Voice Alerts |
| Battery Life | 5 years | 1 year | Shelly Plus Smoke Alarm |
| Connectivity | 2.4 GHz WiFi, Bluetooth | 2.4 GHz WiFi | Shelly Plus Smoke Alarm |
| Integrations | Google Home, Samsung SmartThings, Home Assistant | None | Shelly Plus Smoke Alarm |
| Screen | NO | YES | X-Sense XC0M-iR Smart Carbon Monoxide Alarm with Voice Alerts |
| Sensors | Smoke | CO, Temperature, Humidity | X-Sense XC0M-iR Smart Carbon Monoxide Alarm with Voice Alerts |
| Built-in Light | YES | NO | Shelly Plus Smoke Alarm |
| Local Control | YES | Partially | Shelly Plus Smoke Alarm |
| Rating | 4.4 | 4.4 | Tie |
| Alerts | Fire Alerts, Low Battery Alerts | CO Alerts, Low Battery Alerts | Tie |
| Built-in Siren | YES | YES | Tie |
What the differences mean
What it detects
The Shelly Plus Smoke Alarm senses smoke and fire. The X-Sense XC0M-iR Smart Carbon Monoxide Alarm with Voice Alerts senses carbon monoxide, temperature and humidity but no smoke, so it sits beside a smoke alarm rather than replacing one.
Smart home integration
The Shelly Plus Smoke Alarm works with Google Home, Samsung SmartThings and Home Assistant, supports MQTT and can trigger other devices when smoke appears. The X-Sense XC0M-iR Smart Carbon Monoxide Alarm with Voice Alerts is a closed system with no Alexa, Google Home, HomeKit, SmartThings or Matter, reporting only through the X-Sense app.
Battery life
The Shelly Plus Smoke Alarm is rated for five years on its CR123A battery. The X-Sense XC0M-iR Smart Carbon Monoxide Alarm with Voice Alerts needs a replacement roughly every year on the same cell type.
Warranty
The X-Sense XC0M-iR Smart Carbon Monoxide Alarm with Voice Alerts carries a five-year warranty, two years longer than the Shelly Plus Smoke Alarm's three, which suits an alarm meant to run for years.
Readout and alerts
The X-Sense XC0M-iR Smart Carbon Monoxide Alarm with Voice Alerts has a backlit LCD and spoken alerts that name the room, showing CO, temperature and humidity. The Shelly Plus Smoke Alarm has no display, but it does include a built-in light that the X-Sense lacks.
Which one to buy if
- you want the alarm to feed a smart home automation
The Shelly Plus Smoke Alarm works with Google Home, SmartThings and Home Assistant and supports MQTT, while the X-Sense XC0M-iR Smart Carbon Monoxide Alarm with Voice Alerts cannot trigger anything.
- the home has a gas boiler or an attached garage
The X-Sense XC0M-iR Smart Carbon Monoxide Alarm with Voice Alerts detects carbon monoxide, which the smoke-only Shelly Plus Smoke Alarm cannot.
- you want to avoid changing the battery often
The Shelly Plus Smoke Alarm is rated for five years on one cell, against about a year for the X-Sense XC0M-iR Smart Carbon Monoxide Alarm with Voice Alerts.
- you want the warning spoken out loud
The X-Sense XC0M-iR Smart Carbon Monoxide Alarm with Voice Alerts announces the alarm and its location by voice, while the Shelly Plus Smoke Alarm uses a siren.
- you already run Home Assistant or MQTT
The Shelly Plus Smoke Alarm has a first-class path into those systems, and the X-Sense XC0M-iR Smart Carbon Monoxide Alarm with Voice Alerts does not.
Winner
7% OFF
£65.00
£69.74
- + Battery Life: 5 years
- + Connectivity: 2.4 GHz WiFi, Bluetooth
- + Integrations: Google Home, Samsung SmartThings, Home Assistant
- - Price: £65.00 vs £27.71
- - Warranty: 3 years vs 5 years
16% OFF
£27.71
£32.99
- + Price: £27.71
- + Warranty: 5 years
- + Screen: YES
- - Battery Life: 1 year vs 5 years
- - Connectivity: 2.4 GHz WiFi vs 2.4 GHz WiFi, Bluetooth
What owners say
The two groups bought for different jobs. Shelly Plus Smoke Alarm owners are tinkerers who describe pairing it to 2.4GHz Wi-Fi with no hub and then wiring it into Home Assistant, MQTT and Loxone so a smoke event can push notifications and run scenes, and they praise the loud siren and the five-year battery. Their complaints are the missing CO sensor, no Apple HomeKit or Matter support, no automatic self-test, and a short initial pairing window, with a few reports of false alarms over time. X-Sense XC0M-iR Smart Carbon Monoxide Alarm with Voice Alerts owners like the easy app setup and the push notifications, and they single out the spoken alerts that name the room plus the temperature and humidity readout. They note it is CO only, with no smart home platforms and no interconnection, and that its climate figures lag.
Frequently Asked Questions
Which is better, the Shelly Plus Smoke Alarm or the X-Sense XC0M-iR Smart Carbon Monoxide Alarm with Voice Alerts?
They cover different hazards, so it depends what you need. The Shelly Plus Smoke Alarm is the better smart home device, joining Google Home, SmartThings and Home Assistant and triggering automations, with a five-year battery. The X-Sense XC0M-iR Smart Carbon Monoxide Alarm with Voice Alerts is a dedicated CO alarm with voice alerts, a climate readout and a five-year warranty.
Does the Shelly Plus Smoke Alarm detect carbon monoxide?
No. It is a smoke-only alarm with no CO sensor and no CO alerts, so a separate carbon monoxide detector is needed. The X-Sense XC0M-iR Smart Carbon Monoxide Alarm with Voice Alerts is a CO alarm and does not detect smoke either, so the two are complements rather than substitutes.
Do these alarms need a hub?
Neither needs a hub. The Shelly Plus Smoke Alarm and the X-Sense XC0M-iR Smart Carbon Monoxide Alarm with Voice Alerts both connect directly over 2.4GHz Wi-Fi, with the Shelly also using Bluetooth for pairing. No base station or bridge is required.
How long does the battery last on each?
The Shelly Plus Smoke Alarm is rated for about five years on a CR123A battery, while the X-Sense XC0M-iR Smart Carbon Monoxide Alarm with Voice Alerts is rated for around one year on the same cell type and sends a low battery notification when it is due.
Which one has a display?
The X-Sense XC0M-iR Smart Carbon Monoxide Alarm with Voice Alerts has a backlit LCD that scrolls through the live CO reading, temperature and humidity and stores the CO peak. The Shelly Plus Smoke Alarm has no screen, though it includes a built-in light the X-Sense does not have.
Who should buy the X-Sense XC0M-iR Smart Carbon Monoxide Alarm with Voice Alerts?
A household or renter with a gas appliance, fireplace or attached garage who already has smoke alarms and wants app-connected CO protection with spoken warnings and a temperature and humidity readout, without a base station. Fire coverage that joins a smart home is the Shelly Plus Smoke Alarm's role.
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