Mid-Continent Instruments 4300 Series Installation Manual And Operating Instructions page 14

D. On at least an annual basis, as well as any time there may be a question about battery
performance (life) a Full Capacity Test should be performed. To perform a Full Battery
Capacity Test use one of the following methods.
1. Manual.
a. Disconnect battery pack from the 4300 Attitude I ndicator.
b. Ensure the battery is completely charged and at or near normal room
temperatures (20-25° C). (Ref. Sect. 2.6.1C)
c. Connect the battery to a load of 90 ohms (rated for 10 watts) for 60 minutes
while monitoring the battery voltage level.
a) I f the battery voltage is above 15.0 volts at the end of the 60-minute battery
capacity test, the battery should be capable of continued use after
recharging is complete.
b) I f the battery voltage drops below 15.0 volts before the end of the 60-
minute test period while under load, the battery pack is nearing the end of
its service life and should be replaced.
d. Recharge the battery pack immediately.
2. Automatic.
a. Use MCI Battery Charger/ Tester P/ N 36029. When in the capacity test
mode, this Charger/ Tester will charge the battery and measure the time
required for discharge. (60 minutes minimum) The unit will then
automatically switch to the charge/ float mode to maintain the standby
battery at full charge.
The battery may be permanently damaged if it is left in a
discharged state. Recharge a discharged battery as soon as
possible and maintain w ith a float charge for maximum battery
life.
2.6.2 ATTI TUDE I NDI CATOR
No periodic scheduled maintenance or calibration is necessary for continued airworthiness of
the 4300 series Electric Attitude I ndicator. I f the unit fails to perform to specifications, it must
be removed and serviced by a qualified service facility.
Rev J, September 1, 2009
Mid-Continent I nstruments, Wichita, KS
* * * * WARNI NG* * * *
Manual Number 9015762 Page 15 of 22