The Main battery is rated at ________ amp/hour and the APU battery is rated at ________ amp/hour.

The main battery of the CRJ550 is indeed rated at 17 amp/hour, while the APU (Auxiliary Power Unit) battery is rated at 43 amp/hour. These specifications are important for understanding the power capacities and operational limitations of the aircraft's electrical system.

The main battery provides the initial electrical power needed for systems on the aircraft and can support essential functions during ground operations or when other power sources are unavailable. The APU battery, on the other hand, plays a critical role in starting the APU, which is crucial for providing electrical power and pneumatic pressure when the aircraft is on the ground and the engines are not running.

This knowledge helps pilots and maintenance personnel assess battery performance and ensure that both batteries are adequately charged to avoid power failures during critical phases of operation.