Constant Current Charging; Constant Potential Charging - Piper Cheyenne IIIA Airplane Maintenance Manual

PIPER AIRCRAFT
PA-42-720 (Advanced Trainer)
MAINTENANCE MANUAL
A. DC Generation (continued)
CHART 4
NICKEL CADMIUM BATTERY SPECIFICATIONS
Battery Type: 40776
Capacity: 40 AH at the 1 hour rate
Number of series connected cells - 20 - Nominal Voltage - 24
Constant Current Charging:
Starting rate (Is) - 8.5 to 22 amperes - - Control Point 30.5 volts
Finishing Rate (If) - 4.0 to 10 amperes - - Trickle Rate 215 to 430 milliamps
Constant Potential Charging:
Voltage (Ec) (See Constant Potential Charging V/T Table) 43 amperes min.
Inrush current at above voltage: 350 amperes max.
Floating Voltages:
0°F 29.0 to 31.0 volts
75°F 28.0 to 30.0 volts
100°F 27.4 to 29.4 volts
Discharge Rates:
Max. Short Time:
10 sec. 1720 amperes
30 sec. 860 amperes
Max. Continuous:
430 amperes
1 hour rate: 43 amperes
5 hour rate: 9 amperes
20 hour rate: 2.25 amperes
(Cell) Terminal Type: Screw - - Thread Size: 10/32 - - Torque: 34-38 in. Ibs
Cutoff Voltage:
15.0
20.0
21.0
22.0
Electrolyte Level:
During last 20 minutes of charge
Depth in Baffle:
20 mm
CHART 5
CONSTANT POTENTIAL CHARGING V/T TABLE
Battery Temp. (°F)
0
°
20
°
40
°
60
°
80
°
1000
120
°
140
°
Volts/Cell
Voltage
1.565
1.545
1.525
1.505
1.485
1.460
1.440
1.420
31.3 ± 0.5
30.9 ± 0.4
30.5 ± 0.3
30.1 ± 0.2
29.7 ± 0.2
29.2 ±0.2
28.8 ± 0.1
28.4 ± 0.1
24-30 00
PAGE 17
Jan 10/90
EFFECTIVITY:
040-999