Continued Airworthiness - Mid-Continent Instruments 4300 Series Installation Manual And Operating Instructions

2.6 Continued Airw orthiness
2.6.1 BATTERY
A. The battery is designed to be a user replaceable item if desired. Recommended
replacement interval for the standby battery (P/ N 9015607) is 3 years because of
diminished capacity (See Figures. 2.6 and 2.7 for more information).
B. I n normal use, the 4300-XXX with Battery Backup supplies the proper float charge
voltage to maintain its battery at peak capacity, however, the battery will slowly self-
discharge if the attitude indicator is left unused for long periods (over 3 months). I n
addition, self-discharge rates are directly related to the storage temperature. The higher
the storage temperature the faster the self-discharge rate. Therefore, the battery should
be periodically charged or removed from the installation and maintained on a charger.
C. I f the 4300-XXX Electric Attitude I ndicator with Battery Backup has not been operated
for an extended period (more than 3 months) to keep the battery charged, the standby
battery should be charged by one of the following methods.
1. Keep the battery plugged into the 4300 Electric Attitude I ndicator. Run the unit
overnight (approx. 15 hours) at the rated voltage.
2. Float Charging: Disconnect the battery from the indicator. Connect the battery to a
constant voltage source (battery plug (pin 1) red wire = positive) of 20.4 to 20.6
VDC continuously. Float charging may take 24 hours or longer to charge a
battery pack.
3. Routine Charging: Disconnect the battery from the indicator. Connect the battery to
a constant voltage source (battery plug pin 1 red wire = positive) of 21.6 to 22.1
VDC with a current limit of 0.1 ampere maximum. When the charging current
drops to approximately 5mA, the battery is fully charged and should be
disconnected. Leaving 21.6 to 22.1 VDC charge voltage on the battery for an
extended time will degrade its life. I f continuous maintenance of the charge is
desired, refer to step 2, Float Charging.
Battery out gassing and a rotten egg odor may occur due to
prolonged high rate overcharging and may result in battery
damage. MCI recommends that the battery assembly be replaced if
out gassing has occurred.
4. MCI Battery Charger/ Tester P/ N 36029 may be used. This Battery Charger/ Tester will
apply an initial charge, per step 3 above, and then automatically switch to maintain a
float charge, per step 2 above, indefinitely after initial charging is complete.
Rev J, September 1, 2009
Mid-Continent I nstruments, Wichita, KS
NOTE: The standby battery contains lead. Do not dispose of in local
landfills or other environmentally sensitive areas.
NOTE: Recycle the battery in accordance with state and local
regulations. For recycle locations visit
800-8-BATTERY (1-800-822-8837)
* * * * WARNI NG* * * *
Manual Number 9015762
www.rbrc.com or call 1-
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