Fire alarm battery calculation to be considered

When designing a wired fire alarm system or a wireless fire alarm system, battery calculation must be considered.

BS5839-1 recommends in the event of a power failure, the fire alarm system should be able to operate as normal for 24 hours, and then have enough power to operate the sounders for 30 minutes.

To be able to allowed for this within the fire alarm design, the current load information would be required for all of the fire alarm equipment you are proposing to use.

There is usually less of a concern when dealing with a wireless fire alarm system, as all the external fire detection have their own internal batteries. But the devices within the a wireless fire alarm system, will usually have an A and B, back up supply.