CESSNA®
MODEL 525B
MAINTENANCE MANUAL
STANDBY BATTERY - MAINTENANCE PRACTICES
(Airplanes -0057 and -0451 and On)
1.
General
A.
This section gives the maintenance practices for the standby battery (UN011). The standby battery
supplies electrical power to the L-3 Communications Electronic Standby ESI-1000 Indicator (SFD)
(Airplanes -0451 thru -0664) or the Electronic Flight Display (EFD-750) (Airplanes -0057 and -0665
and On) if the primary electrical power source becomes unserviceable. For a general overview of the
SFD refer to Chapter 34 L-3 Communications Electronic Standby Indicator - Description and Operation
or L-3Harris Electronic Standby Instrument System - Description and Operation.
2.
Tools and Equipment
A.
For a list of tools and equipment, refer to Electrical Power - General.
3.
Standby Battery Removal/Installation
A.
Remove the Standby Battery (Refer to Figure 201).
(1)
Remove the electrical power from the airplane.
(2)
Make sure that the STBY FLT DISPLAY switch, found on the ELECTRICAL POWER switch
panel in the cockpit, is in the OFF position.
(3)
Disengage the STBY BATT CHARGE circuit breaker, found on the left circuit breaker panel in
the cockpit.
(4)
Remove the nose radome to get access to the standby battery (UN011). Refer to Chapter 53,
Nose Radome - Maintenance Practices.
(5)
Disengage the circuit breaker (HN002) that is adjacent to the standby battery.
(6)
Loosen the knurled knob that attaches the standby battery to the tray.
CAUTION:
Do not move the unit from side-to-side or up-and-down when you
pull it out of the mounting tray. Any side-to-side or up-and-down
movement can cause damage to the electrical pin contacts.
(7)
Lift the handle and carefully pull the standby battery straight toward you to disengage it from the
electrical connector (PN017) in the tray assembly.
(8)
Remove the standby battery from the airplane.
B.
Install the Standby Battery (Refer to Figure 201).
(1)
Put the standby battery (UN011) in its position on the tray assembly.
CAUTION:
Do not move the unit from side-to-side or up-and-down when you
push it into the mounting tray. Any side-to-side or up-and-down
movement can cause damage to the electrical pin contacts. Make
sure that the electrical connector pin contacts are aligned correctly.
If they are not aligned correctly, damage to the pin contacts can
occur.
(2)
Carefully push the standby battery to engage it with the electrical connector (PN017) on the tray
assembly.
(3)
Put the knurled knob in its position on the standby battery.
(a)
Tighten the knurled knob.
(4)
Do an electrical bond check (Type I) from the standby battery to the airplane structure. Refer
to the Citation Standard Practices Manual, Chapter 20, Electrical Bonding and Grounding -
Maintenance Practices.
(5)
Engage the circuit breaker (HN002) that is adjacent to the standby battery.
(6)
Do the Standby Battery Operational Check in this section.
(7)
Install the nose radome. Refer to Chapter 53, Nose Radome - Maintenance Practices.
24-36-35
Page 201
© TEXTRON AVIATION INC.
Feb 23/2022
ICA-525B-34-00004
Form 2261 Rev 1
