# X-Sense SD11 Smoke Alarms, 2 Pack, 10-Year Sealed Battery

X-Sense SD11 is a two-pack of battery-powered smoke alarms with a sealed lithium battery claimed to last up to 10 years. The listing also describes a photoelectric sensor, self-check alerts and an 85-decibel alarm. Customer feedback is positive about fitting and loudness, but reports on battery life and durability are mixed.

- [Original product page](https://bargainpostbox.co.uk/product/x-sense-sd11-smoke-alarms-2-pack)
- [View offer](https://bargainpostbox.co.uk/visit/x-sense-sd11-smoke-alarms-2-pack)
- Market: UK
- Language: en-GB
- Currency: GBP
- Brand: X-Sense
- Model: SD11
- Category: Electronics > Smart Home & Security > Alarms & Sensors
- Price: 21.37 GBP
- Previous price: 29.99 GBP
- Discount: 29%
- Price checked: 2026-11-12T17:59:45.819Z
- Rating: 4.5 / 5
- Reviews: 7298

Prices and deal status are the latest recorded data, not a guarantee of availability. Confirm the price and availability with the store.

## At a glance

- Built-in lithium battery is claimed to provide up to 10 years of operation.
- The listing describes a photoelectric sensor, self-checking for faults or low battery, and a low-battery warning.
- LED indicator and silence button are listed as features.
- The manufacturer claims conformity with EN 14604.

## Pros

- Two alarms and mounting hardware are listed in the package contents.
- Customers report straightforward installation and clear instructions.
- Customers describe the warning alarm as loud, consistent with the listed 85-decibel claim.

## Specifications

### Identity
- Brand: X-Sense
- Model: SD11
### Power and battery
- Power configuration: Battery Powered
- Battery life claim: up to 10 years with the built-in lithium battery
### Detection and alerts
- Sensor: photoelectric sensor
- Alarm sound level: 85-decibel
- Standard claim: Conforms to EN 14604 standard
### Dimensions and installation
- Dimensions listed: 12.2D x 12.2W x 4.5H centimetres
- Weight listed: 178 Grams
### Appearance and operating conditions
- Colour: White
- Operating humidity: ≤85%
### Pack details
- Number of items: 2

## Before you buy

- The up-to-10-year battery life is a manufacturer claim, not a guaranteed service period. Customer feedback is mixed, including reports of batteries running out after six months and alarms not lasting two years. Follow the manual for testing and replacement guidance.

## In the box

- 2 × Smoke Alarms (Included)
- 2 × Mounting Brackets (Included)
- Mounting screws (Included)
- 4 × Anchor Plugs (Included)
- User manual (Included)

## A good fit for

- Buyers needing two battery-powered smoke alarms with mounting brackets, screws and anchor plugs listed in the package.
- Those seeking a sealed-battery design with a long stated battery-life claim and self-check alerts.

## Less suited to

- Buyers who require customer feedback showing consistent long-term battery life or durability.
- Buyers seeking a confirmed interconnected or smart alarm system, which is not specified here.

## Customer feedback

Customer feedback highlights easy installation, clear instructions, perceived quality, value and a loud warning alarm. Battery life and durability draw mixed reports, including some accounts of early battery depletion or a shorter-than-expected lifespan. For a sealed-battery alarm advertised for up to 10 years, those reports make long-term reliability an important consideration. Aggregate ratings lean positive overall, but do not explain individual experiences or resolve the mixed durability feedback.
- Positive themes: Customers describe installation as easy and instructions as clear.
- Positive themes: Customers report that the warning alarm is loud.
- Positive themes: Customers express positive views about perceived quality and value.
- Mixed feedback: Customer reports on battery life range from praise for the claimed long duration to reports of depletion after six months.
- Mixed feedback: Durability impressions vary, with some reports that units did not last two years.

## Frequently asked questions

### How many alarms are in the pack?
The listing identifies it as a two-pack, and the included-components list specifies two smoke alarms.
### How long is the battery expected to last?
The manufacturer claims up to 10 years for the built-in lithium battery. Customer feedback on battery life is mixed, so treat this as a claim rather than a guaranteed lifespan.
### What is included for mounting?
The listed package contents include two mounting brackets, four screws and four anchor plugs, alongside the alarms and one user manual.
### Does the listing describe interconnection with other alarms?
No interconnection capability is stated for this SD11 listing.

## Alternative options

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- [X-Sense 2 Pack Smoke Alarm for Home, 10-Year Battery and Lifespan, XS0G-SN \| Conforms to EN 14604 Standard, Test/Silence Button, Standby Without Flashing Light, Ultra-Thin](https://bargainpostbox.co.uk/visit/x-sense-sd11-smoke-alarms-2-pack)
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- [X-Sense Smoke and Carbon Monoxide Alarm with Voice Alerts, XP0A-SR, 1-Pack \| with Replaceable Battery](https://bargainpostbox.co.uk/visit/x-sense-sd11-smoke-alarms-2-pack)
- [FireAngel FA6620 Optical, Battery Powered Fire/Smoke Alarms for Home \| 1-Pack, 10-Year Battery Smoke Alarm Detector, Replacing FireAngel ST-622/ST-620, Fire Alarms for Home](https://bargainpostbox.co.uk/visit/x-sense-sd11-smoke-alarms-2-pack)
- [Wisualarm Wireless Interconnected Smoke Alarm Pre-connected, Smoke Detector for Home, Wireless Interlinked Fire Alarm with 10 Year Battery, 85dB conforms to EN14604 Standard \(5 wireless smoke alarm\)](https://bargainpostbox.co.uk/visit/x-sense-sd11-smoke-alarms-2-pack)
- [FireAngel FA6620 Optical, Battery Powered Fire/Smoke Alarms for Home \| 2-Pack, 10-Year Battery Smoke Alarm Detector, Replacing FireAngel ST-622/ST-620, Fire Alarms for Home](https://bargainpostbox.co.uk/visit/x-sense-sd11-smoke-alarms-2-pack)
- [Smoke Alarm, 10 Years Battery, Smoke Alarms for Home, Fire Alarm with Mute Remotely Function,Big Test/Silence Button Smoke Detectors, Conforms EN14604, UKCA \(5pcs\)](https://bargainpostbox.co.uk/visit/x-sense-sd11-smoke-alarms-2-pack)
- [X-Sense Smoke Alarm for Home with Magnetic Mount, XS0G-SN, 1 Pack \| Standby Without Flashing Light, 10-Year Irreplaceable Battery, Test/Silence Button, Ultra-Thin](https://bargainpostbox.co.uk/visit/x-sense-sd11-smoke-alarms-2-pack)
- [2 Pack Smoke Alarms for Home – 10-Year Life Fire Alarms with 5-Year Replaceable Battery, EN14604 Certified Photoelectric Smoke Detector with Silence Button, LED Light, for Kitchen, Caravan, Office](https://bargainpostbox.co.uk/visit/x-sense-sd11-smoke-alarms-2-pack)
- [X-Sense Smart Smoke, CO & Heat Alarm Kit with Base Station, HSC131-MN \| APP Control, Whole-Home Protect, Magnetic Mounting for Smoke & Heat Alarms](https://bargainpostbox.co.uk/visit/x-sense-sd11-smoke-alarms-2-pack)
- [Smoke Alarm for Home,Smoke Detector with 10-Year Battery,3 PCS \| Magnetic Sticky,Replaceable Battery,BS EN14604 Certification, 85dB Alarm,Test/Mute Button](https://bargainpostbox.co.uk/visit/x-sense-sd11-smoke-alarms-2-pack)

## Add-ons

- [X-Sense Smoke Alarm for Home with 10-Year Sealed Battery, SD11, 2 Pack \| Conforms to EN 14604 Standard, LED Indicator & Silen](https://bargainpostbox.co.uk/visit/x-sense-sd11-smoke-alarms-2-pack)

## Images

![X-Sense SD11 Smoke Alarms, 2 Pack, 10-Year Sealed Battery — 1](https://bargainpostbox.co.uk/i/nokgUg0qCgniRJj6wVR2VDii5C7UMlL_CZH4f2BddvJPsVKmB3n-tq4tbJfRjTQm63EbRLrBZZo0EcNXNWesMWUruDaRyo8qxom4oh8aJhhhWe5N8xVer0Ju.jpg)

![X-Sense SD11 Smoke Alarms, 2 Pack, 10-Year Sealed Battery — 2](https://bargainpostbox.co.uk/i/u5pZgBHF8kTJuJUsEq83181AIVVRncW8Y_rP7spmf_nVlTE3RZcUHuFicIcHCA8ZaND1FN2XSfxMQPqhhUikQrQq0-tPhG3wLmQnfQ6hQTywQY0B8VDJMGbQ.jpg)

![X-Sense SD11 Smoke Alarms, 2 Pack, 10-Year Sealed Battery — 3](https://bargainpostbox.co.uk/i/4Yd5N5R_baOM4-S3-Z41TDwg5n3X-HtXkE2kEgTUajSKJtJt0i9pwqzaCkI8shWgbvBHB_VOCydsj6M64rUQpFCRHACcW15QlXi64ywZIqvEONwn2v3dq2Et.jpg)

![X-Sense SD11 Smoke Alarms, 2 Pack, 10-Year Sealed Battery — 4](https://bargainpostbox.co.uk/i/u62nLBBecogRBei3SdD44JSVt4-foztFu7OmmOXPqZr3Yl3XWz3TgcWcZaA27gHuHiu8cI9MXJS7z3RNU8bIbbgtf2DGB6K5EHkQYISLwuVjCwQOYDjPBLv5.jpg)

![X-Sense SD11 Smoke Alarms, 2 Pack, 10-Year Sealed Battery — 5](https://bargainpostbox.co.uk/i/COH2HbFbDFe2bVyzlwY7ZKxk8LCVX39LoSxRDNzK108wGtn9dLvYqjtKRCAc1wTgwOtSWGOaHKoWg7Z_btVt1UYzywYsS-hsImdvpvZrW3W0OTfNn7FDEhsl.jpg)

![X-Sense SD11 Smoke Alarms, 2 Pack, 10-Year Sealed Battery — 6](https://bargainpostbox.co.uk/i/iOGF1c1anrkKgUa26oAALhcd1FSzaPdfNVDDqm-PkignSxRYdcCPIRH0J3z2xihCPkutxccZ-FHyqCutFICFZidsoUzFxLisxR-_IHUhv5UDo8dh3BsSQ6hp.jpg)

![X-Sense SD11 Smoke Alarms, 2 Pack, 10-Year Sealed Battery — 7](https://bargainpostbox.co.uk/i/p6CZq2jWYAAIyefIDV5NAbYZULbxdgRITmsQEF-Qh1otS14TKIJfja1K2wDze2i-5o-9oEwaQ8ixA4FTaKv-kRBRyxb1rYiVo1UOpKX4QiEZSCkcQ4m23tKa.jpg)