Installation Manual
26
AGM CONSTANT CURRENT CHARGER - IUI
A constant current charger may also be used. However, it is important to adhere
to the termination criteria mentioned below to minimize the chance of excessive
over-charge. See Figure 2 for the recommended constant current charge profile.
AGM BULK STAGE
The charger should deliver the initial current B until the voltage limit A is reached.
Absorption Stage - the charger should maintain the voltage A until the current
tapers to B.
AGM TERMINATION
If the charger can be programmed, the charge should terminate when the
voltage stops increasing over time. This is called a float termination. The charge
should terminate when the float is equal to 2.5mV/cell/hour. The charge time in
the final phase should not exceed 8 hours and the total charge time should not
exceed 20 hours. The percentage recharge should be between 105%-110%.
AGM REFRESH CHARGE
If Rolls AGM batteries are properly charged they should never require an equalizing
charge. If they were not properly charged and there is a decrease in capacity, recharge
the batteries and make sure they complete the entire charge cycle. If the batteries
are stored for extended periods of time, recharge them as follows:
B=Bulk
F=Float
A=Absorption
1.75
0.00
0.20
0.15
0.10
0.25
0.05
0.30
0.35
2.07
2.03
2.00
1.98
1.86
2.00
2.40
2.30
2.20
2.50
2.10
2.60
2.70
B = 0.25 x C20 (1max = 0.35 x C20)
A = 2.45V/Cell (+/- .05V/Cell)
Voltage varies with age
Termination: F= 2.5mV/Cell/hr
or 105-110% recharge
CHARGING TIME: <=16 HRS
CURRENT (X C20 RATE)
VOLTAGE PER CELL
Temperature: 25ºC (77ºF)
Temperature Coefcient: -4mV/ºC/cell (-2mV/ºF/cell)
1
2
=0.01 x C
20
Storage Temperature Refresh Charge Interval
Below 20ºC (68ºF) 9 Months
20ºC (68ºF) - 30ºC (86ºF) 6 Months
Higher than 30ºC (86ºF) 3 Months