Guessing on battery size is an easy way to end up with trouble signals or a failed capacity test. Here is how to get it right.
The battery covers standby load plus alarm load
The battery has to cover the panel’s calculated standby load plus its alarm load. Undersizing it is a common cause of trouble signals and failed capacity tests, because the battery cannot carry the system through the required standby period and then drive the alarm.
Three sizes cover most commercial panels
For most commercial panels it comes down to three sizes: 12V 7Ah, 12V 18Ah, and 12V 33Ah. If you know your panel model we can point you to the size it is specified for. When in doubt, match what is printed on the battery you are pulling out.
Find your size
Browse our fire alarm replacement batteries by size and panel brand. A correctly sized battery is one less line on the most common fire alarm inspection failures.
