Outback Power Systems GS4048A Operators Manual - Manual (Page 34)

Operation
32 900-0161-01-00 Rev A
The remaining charging steps will proceed as described on the previous pages.
Figure 6 Repeated Charging Cycles
Example of Multiple Cycles
 In Figure 6 (Cycle 1), the charger initially completes Absorption. When the Absorption timer expires, the
charger goes Silent until battery voltage decreases to the
Re-Float setting. The Float timer is reset to its
maximum. The charger enters Float and proceeds until it is interrupted by a loss of AC power.
 Cycle 2 begins when the AC source is restored. During the AC loss, the battery voltage did not decrease to
the
Re-Float setting, so Float Time retains the remainder of the previous cycle. The charger returns to Float
and completes the stage when its timer expires. It then goes Silent.
During the Silent period, AC is lost again. The battery voltage decreases until it reaches the Re-Bulk set
point. This causes the charger to prepare a new three-stage cycle from the beginning, but it cannot do so
until the AC source is restored.
In Cycle 1,
Absorb Time had expired. It was not reset afterward and retained a “remaining run time” of zero.
Whenever the battery voltage decreases to Re-Bulk or lower, the Absorption timer will begin accumulating
run time. The first set of arrows below the graph show the length of time accumulated on the Absorption
timer at the end of Cycle 2.
 Cycle 3 begins when the AC source is restored again. The charger begins a new cycle by entering Bulk stage.
When it enters Absorption, the amount of time spent in this stage is equal to the amount of time
accumulated at the end of Cycle 2. (The space between the first and second set of arrows is the same.)
Absorption ends when the timer expires.
This means that the length of Absorption may be shorter than the
Absorb Time setting. During intermittent
AC loss, the batteries may not be used enough to require a total recharge.
In this example, the duration was also longer than the
Float Time setting. Because the Float timer began
running near the beginning of Cycle 3 (when the batteries exceeded the Float Voltage setting), the Float
Time has also expired. The charger does not enter Float and goes Silent.
During the Silent period, AC is lost again. The battery voltage decreases until it reaches the
Re-Bulk set
point, prompting a new charge cycle. The Absorption timer accumulates run time while the batteries are
below this set point.
The first set of barred arrows below the graph show the length of time accumulated on the Absorption
timer. Note that the timer stops accumulating well before the beginning of Cycle 4 when the AC source is
restored. The accumulation of the Absorption timer cannot exceed the
Absorb Time setting.
Voltage
Bulk
(c.c.)
Absorption
Set Point
Float
Set Point
Re-Float
Set Point
Re-Bulk
Set Point
Time
Absorption
(c.v.)
Absorption
(c.v.) Absorption (c.v.)
AC Loss
Float
(c.c.)
AC Loss
Bulk
(c.c.)
Silent
Silent
Float
Timer
(c.v.)
Float
(c.c.)
Float
Timer
(c.v.)
Silent Silent
AC Loss
Timer
accumulates
Timer
accumulates
Timer
runs
Timer
runs
Timer runs
Cycle 4 Cycle 1 Cycle 3 Cycle 2