How is electrical power provided for the emergency lights?

Emergency lights on the A320 are powered through a combination of the DC SCHEDULE ESSENTIAL Bus or via internal batteries located in the light assemblies. This design ensures that in the event of a power failure, the emergency lights can still function independently without reliance on the main battery alone or external power sources such as generators or AC power from the engines. The ability to draw power from internal batteries allows for reliable illumination in emergency situations, which is crucial for passenger and crew safety. This system provides redundancy, ensuring that the emergency lighting is operational even when other electrical systems might be compromised.