The backup battery provides power to which system?

The backup battery provides power to which system?

• A. The backup hot bus, including the GCUS and the EDL
• B. The main hot bus
• C. The central DC bus
• D. The SHED buses

Answer: (A)

The main idea is that the standby (backup) power source is reserved to keep the aircraft’s essential systems alive when normal power is lost. The backup battery specifically powers the backup hot bus, which is the dedicated power path for critical equipment. Keeping the GCUS and the EDL energized on this bus allows the crew to maintain control, monitoring, and essential data functions even during electrical faults. Other buses, like the main hot bus, central DC bus, or SHED buses, are not fed by the backup battery because they support nonessential or different power paths and would quickly exhaust the limited standby power if relied on.

The main idea is that the standby (backup) power source is reserved to keep the aircraft’s essential systems alive when normal power is lost. The backup battery specifically powers the backup hot bus, which is the dedicated power path for critical equipment. Keeping the GCUS and the EDL energized on this bus allows the crew to maintain control, monitoring, and essential data functions even during electrical faults. Other buses, like the main hot bus, central DC bus, or SHED buses, are not fed by the backup battery because they support nonessential or different power paths and would quickly exhaust the limited standby power if relied on.