User manual

VRLA AGM ABSORPTION CHARGE TIME

Where: T = 0.38 x C /I T = ABSORPTION CHARGE TIME

C = 20 hr RATED CAPACITY (total AH capacity of battery bank)

I = Charging Current (Amps) (*see Note: CHARGING CURRENT on pg 11 for details)

0.38 = (factors in assumed current loss during Absorption charge phase)

EXAMPLE:

2 strings of 6 Volt S6-460AGM models

C = 20 hr AH rate = 415 AH x (2 strings) = 830 AH

I = 20% (recommended) of 830 AH = 166 Amps

T = 0.38 x 830/166 = 1.9 hrs

VRLA AGM FLOAT STAGE AND TERMINATION

To maintain 100% SOC, the charger continues output to the battery bank at the

programmed Float voltage and End Amps/Return Amps/Tail Current indefinitely or

until the charger is shut off or unplugged. The profile in Table 6: VRLA AGM

Charge Voltage may be used with or without the Float stage. Without the Float

stage, recharge may be terminated based on time. This will vary by depth of

discharge and charge current, or percentage recharge (105-110%).

ROLLS VRLA AGM BATTERY CHARGE

VOLTAGE PARAMETERS

NOTE: Use the highlighted voltage set points when charge equipment is supplied

with a temperature sensor. Set at 4mV/ºC/Cell...(+/- 96mV per ºC from a 25ºC

Delta - 48V System) Higher or lower settings may cause incorrect adjustments

in charge voltage. Without a temperature sensor, charge settings must be

adjusted manually based on the battery temperature when in use, not just

ambient temperatures.

TABLE 6: VRLA AGM Charge Voltage

NOTE:

If actual measured current is

120 Amps, or the maximum

charger output is limited to

120 Amps, 120 is used.

(Ex. 2 x 60 Amp controllers)

T = 0.38 x 830/120 = 2.6 hrs