Replacing an Emergency Light or Its Battery: What to Know

When is a battery replacement due?

The battery in a self-contained emergency luminaire is a wearing part. Over the years it loses capacity until the luminaire no longer reaches its rated duration – for example one or three hours. Typical reasons for a replacement:

• Failed duration test: the luminaire switches off early during the annual duration test. That is a defect and must be remedied promptly; in Germany, ASR A2.3 requires this without delay.
• Status LED reports a battery fault: what the indications mean is explained in Emergency light flashing red.
• Manufacturer's interval reached: many operators replace batteries proactively at the interval stated by the manufacturer rather than waiting for individual failures.

Not every failed duration test is caused by the battery – charging electronics, light source or an intermittent supply may be responsible, so a professional diagnoses the fault first.

When should the whole luminaire be replaced?

A new battery only makes sense if the rest of the luminaire is in good condition. Replacing the complete luminaire is usually the better option when:

• the electronics or light source are faulty and repair is uneconomic or impossible;
• no suitable replacement batteries are available any more, for example because the manufacturer has discontinued the type;
• older fluorescent luminaires are installed – lamps and spare parts are increasingly hard to source, and LED luminaires use much less energy;
• NiCd batteries are fitted and an upgrade is due anyway. Switching to a lithium battery is only permitted if the manufacturer explicitly approves it, because lithium batteries need different charging electronics;
• the housing, diffuser or pictogram is damaged, yellowed or no longer clearly visible;
• the use of the building has changed and different requirements apply, such as a longer rated duration or a different operating mode.

How a full upgrade works is described in Upgrading emergency lighting.

Who may replace emergency luminaires and batteries?

Both tasks must be carried out by a qualified electrician, or by an electrically instructed person under their direction and supervision. The work involves opening the luminaire and intervening in the electrical installation; it is also a life-safety system whose function must be demonstrated afterwards.

A caretaker or facilities staff without electrical qualifications may, as instructed persons, read indicators, press the test button and report faults – but must not open luminaires or replace batteries, even where the battery appears to be accessible behind a cover. The distinction is explained in Who may test emergency lighting?.

How do professionals approach a replacement?

Without being a step-by-step guide, a proper replacement typically follows this sequence:

• Diagnose the cause: evaluate the fault indication, test records and history to distinguish between battery, electronics and supply faults.
• Choose the replacement: only batteries approved by the manufacturer for that luminaire – type, voltage, capacity and connector must match. For a luminaire replacement, choose one with at least equivalent photometric data, the same rated duration and a suitable operating mode.
• Plan for safety lighting during the work: organise the work so that escape routes are not left unlit, or define interim measures.
• Carry out the work properly: isolate, replace according to the manufacturer's instructions, check the connection and operating mode.
• Allow charging time: emergency luminaires are usually designed to regain their full rated duration within 24 hours.
• Demonstrate function: after charging, carry out a function test and, where appropriate, a duration test; after a luminaire replacement, check that the escape route lighting still meets EN 1838.
• Record it: enter the replacement, date and result in the logbook, ideally with a label inside the luminaire.

How are old batteries and luminaires disposed of?

Old batteries must not go into general waste. Across the EU, the Batteries Regulation (EU) 2023/1542 sets the framework for collection and take-back; producers and distributors have take-back obligations. Example Germany: the Battery Act (BattG) has been followed by the Battery Law Implementation Act (BattDG). Commercial quantities are often returned via the maintenance contractor or the manufacturer. Tape over the terminals of lithium batteries before transport to prevent short circuits. NiCd batteries contain toxic cadmium and must be collected separately with particular care.

Removed luminaires are waste electrical and electronic equipment under the WEEE rules – in Germany the Electrical and Electronic Equipment Act (ElektroG) – and fluorescent lamps are collected separately because they contain mercury. The exact duties depend on the quantity and type of waste; if in doubt, ask your waste contractor. More on battery types and service life in Emergency light battery.

What goes in the logbook after a replacement?

Every battery or luminaire replacement is a repair and belongs in the logbook:

• luminaire number and location, date, qualified electrician who did the work;
• cause and action, for example "failed duration test, battery replaced";
• type of the new battery or luminaire; for a luminaire replacement, update the luminaire list;
• result of the function test after charging.

What makes a logbook complete is explained in Emergency lighting logbook.

Is there an alternative for existing LED luminaires?

Where the general lighting has already been converted to LED, some of those luminaires can be turned into safety luminaires with an emergency driver. An emergency driver is a module with its own battery that keeps the LED luminaire running at reduced output during a mains failure. NOTLUX offers emergency drivers for existing LED luminaires and an IP65 version for LED high-bay luminaires up to 300 W, each with 90 minutes of emergency operation. The converted luminaire must meet the requirements for safety luminaires; where a rated duration of 3 hours is required, 90 minutes is not sufficient.

How can battery replacement be planned?

A fixed maintenance cycle stops battery replacement from turning into an emergency repair. NOTLUX luminaires contain a LiFePO4 battery that can be replaced at the luminaire, with a service life of at least five years. The NOTLUX maintenance contract includes one on-site inspection per year, replacement of all batteries in year 5 to 6 and repairs during the contract term, with every inspection documented digitally.