ICON A5 MM : Electrical System : Battery : Maintenance Instructions : Charge Battery
Charge Battery
100081-00
Use this procedure to boost-charge the aircraft battery.
Applicable Aircraft Serial Numbers
All
Type of Maintenance
Line
Level of Certification
Owner/Pilot
Task Specific Training Required
No
Special Tools Required
A 14.125±.125 VDC charge with current capability of at least 4.8 amperes for AGM batteries.
Parts Required
None
Aircraft System
03—Electrical System
Safety Equipment
As Needed
Consumables
None
IPC Reference
Warning: 
Do NOT jump start the aircraft.
Task Instructions
1. Verify that master switch OFF.
2. Remove red and black terminal caps from positive and negative charging terminals, respectively. (Figure 42)
Figure 42. Aircraft Battery Charging Terminals
3. Use a multimeter to check the battery voltage. If battery voltage is below 12.6 VDC, charge battery.
4. Remove the multimeter from the battery charging terminals.
5. Verify that your charging unit is OFF.
Warning: 
Make sure to use an AGM compatible charging system for the battery. Because AGM batteries are sensitive to overcharging, the recommended charge rate should be kept around 2.25-2.30V/cell and shall not exceed 2.40V/cell.
6. Attach positive charging clamp from charging unit to the positive charging terminal.
7. Attach negative charging clamp from charging unit to the negative charging terminal.
8. Turn on the charging unit. Boost-charge battery up to a minimum of 12.6 VDC. Do not exceed 192 amperes charge current.
Warning: 
Do NOT jump start the aircraft battery.
Continue charging for four more hours after the charge current drops to 1.2 amperes. See Table 8 for state of charge (SOC). Turn off charging unit once charging is complete.
Table 8. Battery Charging Status Reference
Open Circuit Voltage (VDC)
SOC(%)
12.9 or above
100
12.6
75
12.3
50
12.0
25
11.7 or below
0
Source: Concord RG Series Aircraft Battery Owner/Operator Manual (5-0324 Rev D)
10. Remove negative charging clamps from the aircraft battery charging terminals.
11. Remove positive charging clamps from the aircraft battery charging terminals.
12. Use a multimeter to verify that the battery voltage is at or above 12.6 VDC.
13. Replace the red and black terminal caps. (Figure 42)
Verification Method
Turn the master switch ON. Verify that the BATTERY indicator does not stay lit in the annunciator panel.
Note: 
If the battery requires charging after normal aircraft operation, the battery may be faulty and must be replaced.