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Mains Powered Carbon Monoxide Alarm with Lithium Back-up Battery - BRK CO850MRLi

Available to order Expected dispatch: 3rd Nov
£57.59 inc VAT
£47.99 ex VAT
Product Overview
The CO850MRLi is a mains powered carbon monoxide (CO) alarm installed with a tamper-proof, rechargeable lithium back-up battery to ensure the continuation of the alarm's functionality in the event of mains failure. The alarm can hardwire interlink with up to 12 compatible carbon monoxide alarms to provide a simultaneous warning and is supplied with a 5 year manufacturer's warranty as standard. Coloured indicators are used to display power, alarm and faults so any problems can be identified quickly.
  • 230V mains powered carbon monoxide alarm
  • Fitted with a tamper-proof, rechargeable lithium back-up battery
  • Kitemarked to BS EN 50291-1:2010
  • 5 year manufacturer's warranty
  • Loud 85dB warning alarm at 1m
  • Power, alarm and fault indicators
  • Hardwire interlink with up to 12 compatible devices
  • Combined test and reset button
  • Dimensions (HxWxD) 134x69x60mm
  • Product warranty and life commences from date of purchase
Technical Data
Product Code BKCO850MRLI
Alternative Product Codes CO850MRLI
Brand BRK
Back-Up Battery

Sealed lithium

Dimensions (HxWxD)


Sound Output



5 years

Weight 0.23kg
Product Datasheets
FAQs (6)
Q. Is this CO Detector compliant with all relevant standards to allow me to place it in a tenanted property as I am a landlord?

Yes, this CO alarm has been Kitemarked to EN 50291-1: 2010 and has been awarded a CE mark. It should be installed in line with the manufacturers guidance.

Q. How do I safely dispose of my old smoke alarms?

Safelincs is signed up to Valpak's WEEE (Waste Electrical and Electronic Equipment) Distributor Take-Back Scheme (Registration ID: 7370). Private households can therefore drop off their electronic and electrical fire safety waste at their municipal recycling centre when they are purchasing new products from us. To find your nearest recycling centre, please visit

Q. How long do the batteries last in smoke alarms?

The 9V alkaline batteries last 12-18 months. Lithium batteries will usually last 5x longer than their alkaline counterparts, achieving around 5 years lifetime. Some lithium cells are also rechargeable, and when used in a mains-powered alarm may last for the entire functional lifespan of the alarm. Newer alarm models may also feature a "sealed" lithium battery. These batteries are specialist components which are designed to not be removed or need replacing by the user, and have been tested by the alarm manufacturer to ensure they last for the lifetime of the alarm.

Please Note: the actual lifetime of your batteries depends on how often the alarms are tested or activated, as sounding the alarm draws more power than when the alarms are "waiting" to detect fire. You should also read your alarm's manual to make sure you only use the recommended types and brands of batteries, as failing to follow these instructions may cause the alarm to malfunction, not alerting you in the event of a fire, and might also invalidate the warranty.

Q. Do you need an electrician to connect mains powered smoke alarms?

It is necessary that an electrician installs mains powered smoke alarms.

Q. What is the best way to test my alarm?

We recommend testing alarms by pressing the test button built-in to the unit, as this is designed to simulate the detection of the target stimuli (usually smoke, heat, or CO) at the alarm sensor. You should test your alarms regularly to ensure they are protecting building occupants, preferably every week. For more detailed guidance, check the manual included with your alarm.

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Pricing & Availability

Model Stock Price
Product Code: BKCO850MRLI Stock Level:
Available to order Expected dispatch: 3rd Nov

£57.59 inc VAT

£47.99 ex VAT

Delivery Options

The following delivery options are available on this product.

Economy Delivery

£4.79 inc VAT - Orders will be delivered in 8-10 working days by Hermes

Expedited Delivery

£7.91 inc VAT - Orders will be delivered in 6-7 working days by Hermes

Excellent Warranty

This product is supplied with a 5 year manufacturers warranty as standard

Looking for more information?

If you have any questions or would like more information about this product you can ask one of our specialists.

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Direct Telephone 01507 464181


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