Emergency light fails its discharge test
An emergency fitting works on mains but won't stay lit for the required duration when tested (mains removed) — usually a failed/aged battery, but can be charging or lamp issues.
Safety first
These are life-safety fittings — a failed-duration light won't protect occupants in an outage. Isolate before working; licensed work with testing/record requirements.
Isolate, lock out / tag out, and prove dead before working unless a live test is specifically required, authorised, and carried out under proper supervision. Always follow local regulations, your site procedures, and the equipment manufacturer's documentation.
Apprentice mode
Full walk-through — the why, what readings mean, mistakes & safety.
Likely causes
Ranked from most to least likely.
- 1
Aged / failed battery
Most likelyThe rechargeable battery has lost capacity and can't sustain the required duration — the most common cause.
- 2
Charging circuit fault
#2The fitting isn't charging the battery properly (so it's never fully charged).
- 3
Lamp/LED or inverter fault in emergency mode
#3The emergency lamp/LED or its inverter underperforms when on battery.
- 4
Battery not given enough recharge time before test
Least likelyTested before fully recharged from a previous discharge.
Reports are saved on this device to reflect what you actually find.
Testing sequence
Work through one test at a time. Expected reading and what each result means.
On the tools? Job Mode shows one test at a time with thumb-sized buttons — your place and readings carry straight over.
Enter Job ModeConfirm the fitting has had adequate charge time, then run the full-duration discharge test per procedure.
Maintains the required output for the full rated duration.
Passes after proper charge — it may have been under-charged.
Fails duration even after charging — suspect battery/charging.
View all expected readings at once
Fault-finding flowchart
The same logic as a decision tree.
- 1start
Emergency light fails test
→ step 2 - 2decision
Does it pass after a proper full recharge?
Yes→ step 3No→ step 4 - 3result
It was under-charged — re-test on schedule and record.
- 4decision
Are charging and battery healthy?
Yes→ step 5No→ step 6 - 5result
Check the emergency lamp/inverter; replace the fitting if needed.
- 6result
Aged/failed battery or charging fault — rectify and re-test.
Common mistakes apprentices make
- Testing before the battery is fully recharged.
- Replacing the lamp when the battery has failed.
- Not recording the test outcome.
- Leaving a failed-duration fitting in service.
When to stop & escalate
Emergency lighting testing/records are governed by scheduled requirements — failed fittings must be rectified and re-tested by a licensed person and the results recorded.
If you're past your competence, authorisation, or the safe limits of the job — stop and hand it on. There's no fault worth getting hurt over.
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An emergency fitting stays in emergency (battery) mode or its charge/fault LED stays wrong even with normal supply present — pointing at the supply sensing, charging, or the fitting.
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Learn the theory
How the gear and circuits behind this fault actually work.