Mains Powered Carbon Monoxide Alarm with Alkaline Back-up Battery - BRK CO850MBXi

There is no legal or BSI requirement to test the CO detectors with a test gas. A weekly check with the test button is fully sufficient if you choose a quality CO detector. The test gas is offered as a 'belts and braces' option.

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

The 9V alkaline batteries and AA alkaline batteries generally last 12 to 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.

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.