Instruction Manual

745-680-B11-001, Rev. A
12
2.1 General Charge
The limited current and constant voltage recharge method, also known as the modied
constant potential method, satises the need to have the battery quickly recharged while
ensuring maximum battery life. Figure 2-1 shows the relationship between current, voltage,
and charge for the SMU-C 12-100.
When to Charge
After installing or discharging the battery.•
If the battery has been stored for more than three months and the open circuit voltage is •
lower than 12.6V/block.
General Charge Procedure
Charge the batteries with a constant current no greater than 0.2C1.
20
A until an average
voltage of 13.8V/block at 77ºF (25ºC) is reached.
Continue charging, reducing the current to maintain a constant voltage of 13.8V/block.2.
Fast Charge Procedure
Charge the batteries with a constant current no greater than 0.2C1.
30
A until an average
voltage of 13.8V/block at 77ºF (25ºC) is reached.
Continue charging, reducing the current to maintain a constant voltage of 13.8V/block.2.
The batteries will be fully charged in 18-24 hours when the voltage is a constant 13.8/3.
block and the charge current has not needed adjustment for three continuous hours.
If the heat generated as a result of charging exceeds the rate at which heat can be transferred out
of the battery, thermal runaway can occur and excessive overheating will result.
NOTE:
Take measurements before and after charging and during discharge to help track changes and problems. Use
a form (see Section 6.0), to record the results. Wait two hours after charging before taking nal measurements
in order to allow the electrolyte to cool sufciently.
NOTE:
Refer to your particular charger’s manual for specic instructions regarding charger setup and operation.
Fig. 2-1, Charge Characteristics Curve
(SMU-C 12-100 with initial 0.1C
20
A current and limit voltage 13.8V/Cell)
2.0 Charging Procedures
50%Discharge
100
120
80
20
0.05
60
40
0.25
0.10
0
0.20
0.15
100%Discharge
0
2.33
2.17
2.00
1.83
0
2
4 6
8
10 12
Charge Characteristic
Constant Charge at 25.0A-13.80V (25°C)
Charge Capacity (%)
Charge Current (CA)
Charge Voltage (V/Cell)
Time (Hours)
Charge Voltage
Charge Capacity
Charge Current
CAUTION!