The annual 90-minute emergency lighting test
Once a year, every battery-powered emergency light and exit sign must run on battery for the full 90 minutes. It is the test that catches failing batteries.
Why the 90-minute test matters
NFPA 101 requires emergency illumination to last at least 90 minutes after normal power fails, so once a year each battery unit has to prove it can. This is the test that exposes aging batteries: a unit can pass every 30-second monthly test and still go dark at minute 40 of a real outage. If you only do one test well, do this one.
How to run it
- Schedule around recharge. Batteries need many hours to recharge after a full discharge, so test when the building can tolerate reduced backup for the rest of the day, and avoid testing right before a storm.
- Start the test. The traditional way is to turn off the breaker feeding the units for 90 minutes. On One Touch units, press the button twice to start the 90-minute test on that unit with no breaker.
- Check at the end. At 90 minutes, walk the route. Every lamp and sign should still be lit at usable brightness.
- Record and fix. Log the result for each unit. Replace batteries or units that failed, then retest.
The breaker problem
Shutting a breaker for 90 minutes affects every load on that circuit, so the test gets scheduled after hours, coordinated with tenants and often skipped. That is the hazard GLS was built to remove: the One Touch double press runs the annual test unit by unit, and self-testing models run it on their own every year.
What to do with failures
A unit that cannot reach 90 minutes almost always needs a new battery. If the unit is old or out of production, replacing it with a self-testing unit removes next year's manual test. See battery replacement guidance in our battery guide.
Frequently asked questions
How long is the annual emergency lighting test?
At least 90 minutes (1.5 hours), once a year, under NFPA 101.
Do I need to turn off the breaker for the annual test?
Traditionally yes. One Touch units run the 90-minute test with two presses of the button, and self-testing units run it automatically, so no breaker shutdown is needed.
How long do units take to recharge after the test?
Many hours. Check the manufacturer's recharge time and schedule the test so the building is not left without full backup during a risky period.