Do you know about the emergency light fittings?

Do you know what the emergency lighting fittings are? 

Emergency light fittings include a continuous charging the battery as a backup power supply, emergency lighting accessories can be told when the power supply has failed, and immediately switched to the backup battery. The battery needs to emergency lamp charging at least 3 hours. In order to save power, reduce the light output from the fitting, often to 10 normal light output .

What is the difference between the parts that are maintained and not maintained?

Equipment maintenance, will serve as a normal light fitting and control all the other lights in the area, however, when the power failure, keep emergency accessories will continue to run, but in the low light efficiency. Maintenance accessories, normally closed, the battery is continuously charged, a green LED display fully charged. When the power failure, and then use the battery supply switch fittings. Part of the repair parts is not for general lighting, but accessories for fire emergency exit sign.