A self-contained emergency luminaire is an emergency light with its own battery, charging and control electronics and LED light source: in normal operation the mains keeps the battery charged, and when the mains fails the luminaire switches to battery operation automatically and stays lit for its rated duration, for example one or three hours. When the mains returns, it switches back to normal mode and recharges the battery. Because each luminaire works independently, a self-contained system needs neither a battery room nor fire-resistant cabling to a central unit.
What is a self-contained emergency luminaire?
A self-contained emergency luminaire is an emergency luminaire that carries its own energy source for emergency operation. The requirements for such luminaires are set out in EN 60598-2-22. They come as exit sign luminaires, which mark the escape route, and as emergency luminaires that illuminate escape routes and open areas.
In group and central battery systems, by contrast, all luminaires are supplied from a shared battery via a dedicated wiring network. How the systems compare overall is shown in self-contained vs central battery; the central variant is described in central battery system.
How is a self-contained luminaire built?
A modern LED emergency light with its own battery consists essentially of four assemblies:
| Assembly | Function |
|---|---|
| Battery | Stores the energy for emergency operation, today usually LiFePO4 or another lithium chemistry |
| Charging and control electronics | Charges the battery, monitors the mains voltage, switches over on mains failure and protects the battery against deep discharge |
| LED light source with optic | Produces the light; the optic distributes it to suit escape route, open area or pictogram |
| Status LED and possibly radio module | Shows readiness, charging or fault; networked luminaires also communicate via bus, radio or Bluetooth |
Add to this the housing, terminals and, for exit sign luminaires, the pictogram to ISO 7010.
How does a self-contained luminaire work in operation?
The sequence can be divided into three states:
- Normal mode: the luminaire is connected to the normal supply. The charging electronics keep the battery permanently charged, and the status LED shows that the luminaire is ready.
- Emergency mode: if the mains voltage fails or drops below a defined threshold, the electronics switch automatically to battery operation. The LED stays lit until the mains returns or the rated duration is reached. Response times and illuminance levels are set out in EN 1838.
- Return and recharging: once the mains is back, the luminaire switches to normal mode and recharges the battery. EN 60598-2-22 requires the rated duration to be available again after 24 hours of charging. Until then, emergency readiness is limited.
Note that the luminaire reacts to its own supply cable. So that it also switches on when only the general lighting in one area fails, it is usually connected to the same circuit as that general lighting.
Non-maintained or maintained mode?
Self-contained luminaires can be operated in two modes:
| Mode | Behaviour | Typical use |
|---|---|---|
| Non-maintained | Off in normal operation, switches on only when the mains fails | Emergency luminaires illuminating escape routes and open areas |
| Maintained | Lit continuously while the building is in use and stays on when the mains fails | Exit sign luminaires in many workplaces and places of assembly |
Many luminaires can be switched between modes, for example by a link at the terminal or via an app. Which mode your building requires depends on national building law, the building permit and the fire safety strategy; see types of emergency lighting.
What do the status LED and self-test do?
The status LED shows at a glance whether the luminaire is ready, charging or faulty. Colours and flashing patterns vary by manufacturer; what a red indication usually means is explained in emergency light flashing red.
Self-testing luminaires to EN 62034 carry out the monthly function test and the annual duration test automatically. Results are read via the status LED, a central panel (bus or radio) or an app. The duty to carry out visual checks, review results and keep records remains with the operator. Details are given in self-testing emergency lights.
Which battery is in a self-contained luminaire?
Common chemistries are nickel-cadmium (NiCd), nickel-metal hydride (NiMH) and lithium batteries, above all lithium iron phosphate (LiFePO4). LiFePO4 is regarded as long-lived, thermally stable and free of memory effect; NiCd is being displaced because of its toxic cadmium content. Conventional NiCd and NiMH batteries are often replaced after four to five years in practice.
Every battery is a wear part and loses capacity over the years, faster at high temperatures inside the housing. That is why the annual duration test matters so much. NOTLUX luminaires use a replaceable LiFePO4 battery with a service life of at least five years. Chemistries, service life and replacement in detail: emergency light battery.
What is an emergency driver?
An emergency driver (also called an emergency conversion module) is a unit of electronics and a separate battery that turns a standard LED luminaire into a self-contained emergency luminaire. In normal operation the luminaire runs on its own LED driver; when the mains fails, the emergency driver powers the LED module from the battery at a reduced emergency output.
This is particularly useful in upgrades: existing LED fittings such as panels or high-bay luminaires also take on the emergency lighting function, so no additional luminaires need to be installed. The luminaire and driver must be suitable for the combination, and the EN 1838 requirements must be met in emergency mode. More in upgrading emergency lighting.
What are the pros and cons of self-contained luminaires?
| Advantages | Disadvantages and limits |
|---|---|
| No battery room or electrical operating room needed | Many individual batteries to test and replace |
| No fire-resistant cabling to a central unit | Maintenance is spread across many devices in the building |
| A failure affects only one luminaire | High or very low ambient temperatures strain the battery |
| Luminaires can be added or moved individually | Without self-test, high testing effort per luminaire |
| Uses the existing supply, well suited to existing buildings and retrofits | With very many luminaires a central solution may be more economical |
With self-testing luminaires and long-life LiFePO4 batteries, the traditional drawbacks are much smaller than they used to be. The permitted ambient temperature is stated in the luminaire's datasheet and should be checked for installations under roofs, in plant rooms or in cold areas.
How are self-contained luminaires tested?
Self-contained luminaires are subject to the same testing duties as centrally supplied systems. The European basis is EN 50172; in Germany, for example, DIN EN 50172 (VDE 0108-100):2024-10 replaces the former pre-standard DIN VDE V 0108-100-1 (transition period until 27 May 2027):
| Interval | Test |
|---|---|
| Monthly | Function test: switch to emergency mode, every luminaire lights up, then return to normal mode |
| Annually | Duration test for the full rated duration |
| Every 5 years | Measurement of illuminance in emergency mode (DIN EN 50172:2024 in Germany) |
There are no daily indicator checks because there is no central unit. The testing basis should be defined and recorded in the logbook for each installation, as existing systems may still be subject to older national requirements. All intervals at a glance: emergency lighting testing intervals.
Practical tip: Schedule the annual duration test outside occupied hours and allow for the batteries needing up to 24 hours to recharge afterwards. Self-testing luminaires can often be programmed to run these tests in staggered groups.
Which self-contained luminaires does NOTLUX offer?
All NOTLUX Series 19 products work as self-contained systems with automatic self-test in line with EN 50172 and EN 62034, plus Bluetooth and app for the digital logbook: exit sign luminaire, escape route luminaire, compact emergency light and recessed downlight with LiFePO4 battery and up to 3 hours of emergency operation, as well as emergency drivers with Li-ion battery and 90 minutes of emergency operation for existing LED luminaires. The NOTLUX maintenance contract includes one on-site inspection per year, replacement of all batteries in year 5 to 6 and repairs during the term.
Frequently asked questions
How does a self-contained emergency luminaire work?
The luminaire is connected to the mains, which keeps its built-in battery permanently charged. If the supply fails, the electronics switch to battery operation automatically and the LED stays lit for the rated duration. When the mains returns, it switches back and recharges the battery.
How long does an LED emergency light stay on during a power cut?
For its rated duration, typically one or three hours depending on the building's requirements. Which duration applies is explained in emergency lighting duration.
How long does recharging take after a power cut?
EN 60598-2-22 requires the full rated duration to be available again after 24 hours of charging. Allow for this charging time after longer power cuts or the annual duration test.
How long does the battery in a self-contained luminaire last?
That depends on chemistry, temperature and the manufacturer's specification. NiCd and NiMH batteries are often replaced after four to five years, while LiFePO4 batteries with suitable electronics usually last longer. NOTLUX luminaires use replaceable LiFePO4 batteries with a service life of at least five years.
Do self-contained luminaires need fire-resistant cabling?
Not for the emergency supply, because the battery is inside the luminaire. If the supply cable fails, the luminaire switches to its battery. Circuit-integrity requirements mainly concern cables through which a central battery supplies its luminaires.
Can a standard LED luminaire be converted into an emergency light?
Yes, with an emergency driver, provided the luminaire and driver are suitable for the combination. In emergency mode the lighting requirements of EN 1838 must be met; this should be designed and checked by a specialist contractor.
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