If it does not light up for the entire thirty seconds you have a bad exit sign battery.
Exit sign light not working.
Plus leds consume less energy than incandescent bulbs saving you money over the lifetime of the exit sign.
In some larger buildings emergency power to exit signs and emergency light fixtures is provided by an emergency generator.
Checking multiple emergency or exit sign for bad batteries.
The signs require troubleshooting as soon as anything starts to go wrong with them.
Therefore an exit sign that appears to be working normally may not work at all during a power failure because the low voltage bulbs have burned out.
Led exit signs last for decades without burning out making this a convenient upgrade.
Therefore an exit sign that appears to be working normally may not work at all during a power failure because the low voltage bulbs have burned out.
Keeping emergency exit signs in working order is a high priority.
In some larger buildings emergency power to exit signs and emergency light fixtures is provided by an emergency generator.
Replacing an exit sign is a fairly straightforward do it yourself job if you have a bit of experience with electrical work.