Folks
Elio Addict
The EL stuff they use for inside buildings (emergency egress lighting) is powered by the lights while the regular lights are on, and after the lights are off, it glows for about 1-2 hours, I don't know if it is the same thing.
Emergency lighting is simply a small gel cell battery to run a 12 volt light. The battery is trickle charged and held in the off position as long as normal power is present. When 110 Power fails and a make contact relay closes and activates the 12 volt light for a long as the battery holds out. When power returns the 12volt circuit once again turns off and is returned to the continuous trickle charging of the 12 volt for future failures.