In normal mode, the central battery unit’s task is to monitor mains voltage, charge batteries, and feed the maintained light groups. During a power failure, the central battery unit feeds the non-maintained and maintained light groups with the energy stored in the batteries. Any failure of the system will impact the whole infrastructure during emergencies. The safety of the personnel and assets are more important. In order to keep the system up & to run, it requires Planned Preventative Central Battery System Maintenance by an experienced Professional.