Emergency lighting full duration test
Once a year, the mains supply is disconnected and every emergency light is run on battery for its full rated duration — normally 3 hours — to confirm it stays bright enough for the whole period.
Once a year, the mains supply is disconnected and every emergency light is run on battery for its full rated duration — normally 3 hours — to confirm it stays bright enough for the whole period. This is a different, longer test to the brief monthly "flick test" of the switch.
A battery that lights up fine for a monthly 30-second check can still fail after 20 minutes under real load. The only way to know your escape lighting will actually last through an evacuation is to run it for the full duration and watch what happens.
Ask them to log every luminaire individually, not just "system passed".
Who this is for
Any venue with emergency escape lighting — effectively all commercial premises.
What you’ll hold
- Full duration discharge test certificate
- Emergency lighting log book entry
Watch out for
- Running the discharge test on a normal trading night, so if the mains genuinely drops mid-test the venue has no working escape lighting for real.
- Not allowing a full recharge (commonly around 24 hours) before the next service — batteries tested again too soon read as failed when they are simply still charging.
- Treating the monthly flick test as good enough and skipping the annual full duration test altogether.
Sources
- BAFE — Emergency lighting system guidance checked 2026-09-02
See also
- Emergency lighting to BS 5266— this becomes part of getting open →
- Emergency lighting function test
- Fire risk assessment review
This is item 12 of 60 in the free UK Compliance Calendar. See the whole list →