How often do commercial fire alarm system batteries need to be replaced?

Most commercial fire alarm control panels use sealed lead-acid backup batteries, which typically need replacement every 3–5 years, depending on manufacturer and usage. However, NFPA 72 doesn't set a fixed replacement calendar — instead, it requires an annual battery test confirming the batteries can still power the system for 24 hours on standby plus 5 minutes in full alarm. If a battery fails that test, or shows visible swelling, leakage, or corrosion, it must be replaced immediately regardless of age. Ace Fire Systems includes this testing as part of our standard fire alarm inspection service across Nevada, Utah, and Arizona.