What is the purpose of a standby battery on the ERJ-145?

What is the purpose of a standby battery on the ERJ-145?

• A. To power standby instruments and critical systems on the Standby Bus if primary power is lost.
• B. To power the Main AC Bus.
• C. To power left engine only.
• D. To charge external power.

Answer: (A)

The standby battery is there to keep essential flight information available when normal power is lost. It powers the Standby Bus, which provides the standby instruments (like attitude, altitude, and airspeed indicators) and other critical systems. This lets the pilot maintain situational awareness and basic control even if the primary electrical sources fail, until power can be restored or backups are re-established. It isn’t used to power the Main AC Bus, it doesn’t serve just one engine, and it doesn’t charge external power.

The standby battery is there to keep essential flight information available when normal power is lost. It powers the Standby Bus, which provides the standby instruments (like attitude, altitude, and airspeed indicators) and other critical systems. This lets the pilot maintain situational awareness and basic control even if the primary electrical sources fail, until power can be restored or backups are re-established. It isn’t used to power the Main AC Bus, it doesn’t serve just one engine, and it doesn’t charge external power.