Emergency lighting · BS 5266-1
Emergency lighting testing: monthly, annual and what to record
The monthly function test, the annual full-duration test, central battery readings, and what a compliant emergency lighting record actually needs to show.
The two tests that matter
Emergency lighting maintenance under BS 5266-1 comes down to two recurring tests, plus a visual check that the installation still matches the building:
| Test | What it proves | How often |
|---|---|---|
| Function test | Every luminaire switches to emergency mode when the supply is interrupted | Monthly |
| Full-duration test | Every luminaire stays lit for its rated duration (usually 3 hours) on battery alone | Annually |
The monthly test is short — long enough to see each fitting illuminate, not long enough to drain the battery. The annual test runs for the full rated duration and is the one that actually reveals a tired battery.
The monthly function test
Interrupt the normal supply to the emergency luminaires (usually via a key switch or test facility), confirm every fitting and exit sign illuminates, restore the supply, and confirm the charging indicators come back on. Any fitting that fails to illuminate is recorded and fixed.
This is normally done by the responsible person on site and logged in the site's emergency lighting log book. It doesn't need an engineer, but it does need doing — a year of missing monthly entries is a common audit finding.
The annual full-duration test
Once a year each luminaire is run on battery for its full rated duration — three hours for a three-hour system. At the end, every fitting should still be lit. Fittings that go dark early have batteries that no longer hold their rated capacity and need replacing.
Timing the test: because the batteries need time to recharge afterwards, the annual test should be done when the building can tolerate reduced emergency cover for the recharge period — typically outside occupied hours, or in stages across a building with more than one circuit.
For self-contained luminaires the result is per fitting. For central battery systems the duration test is on the central unit, with the individual fittings checked for illumination, and the battery readings recorded.
Central battery systems: the readings
Where a site has a central battery unit rather than self-contained fittings, the annual visit should record float voltage, on-load voltage, charger output and the load current, and assess whether the battery capacity still meets the design duration. As with fire alarm standby batteries, the assessment is a calculation from the readings — writing the numbers down without doing the sum leaves the certificate unable to say whether the system is actually compliant.
Does the installation still match the building?
Emergency lighting is designed around escape routes, open areas and high-risk task areas. Buildings change: a new partition wall, a re-hung door or a rearranged warehouse can leave part of an escape route unlit. The annual visit should include a walk of the escape routes against the current layout, and the certificate should say whether coverage is still adequate.
What the record has to show
- The site and system, and whether it's self-contained or central battery
- The date, the type of test (function or full-duration), and who carried it out
- A luminaire-by-luminaire result for the annual test, including the duration achieved
- Central battery readings and the resulting capacity assessment, where applicable
- Every defect, with a severity and recommended action
- An overall verdict and the next test due date
Kerova's emergency lighting certificate holds the luminaire register, the duration results and the central battery readings, computes the verdict, and reminds the client before the next annual test is due.
This guide is general information for UK fire & security companies, not legal or engineering advice. Always work to the current edition of the relevant standard and your own competent-person judgement.
See this on a real certificateKerova builds the register, readings and verdict into the certificate itself.
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