OutBack Power Owner's Manual

Status and Information
32 900-0209-01-00 Rev B
Absorb
The system display shows this message for the Absorption stage of a three-stage cycle. In this stage,
the FLEXmax 100 regulates the battery voltage at the Absorb Voltage set point. This stage is
temperature-compensated. (See page 68.) Absorption is a constant-voltage, variable-current charging
stage. It usually involves a tapering current flow. However, it may deliver no current and still display
Absorb if another source maintains the batteries above the Absorb Voltage set point.
While the batteries are held at this voltage, the internal timer counts up from zero toward the Absorb time
setting. (See pages 36, 42, and 67.) The charger will exit this stage and enter the Float stage if the timer
reaches the time limit, or if the Absorb End Amps setting is reached. (See page 42.)
The absorption timer is internal to the FLEXmax 100 and is not displayed as a real-time reading.
However, the Absorb reading shown on page 36 will display the total time spent in Absorption that day.
Figure 22 LED Indicators (Absorb)
If the battery voltage drops below the Absorb Voltage set point before the Absorb time is reached (see
page 42), the FLEXmax 100 reverts back to the Bulk charge stage. The system display shows Bulk as
shown on page 36.
The internal timer may not always begin at zero if the last charge was interrupted or ended early. If the
batteries drop below the voltages noted on Table 3, the timer will begin counting down toward zero. This
adds to the duration of the next Absorption stage. If the timer reaches zero, it will last for the full duration
of the Absorb time setting.
Lower voltages will cause the timer to subtract minutes at a faster rate, as shown on Table 3. These
voltages indicate a significantly greater battery discharge, requiring a much longer charge cycle.
Table 3 Absorption Timer
Battery Voltage Timer Activity
 24.8 V, 37.2 V, or 49.6 V, and less than
the Absorbing voltage
No change.
< 24.8 V, 37.2 V, or 49.6 V
For every minute elapsed, 1 minute is
subtracted from the timer
< 24.0 V, 36.0 V, or 48.0 V
For every minute elapsed, 2 minutes is
subtracted from the timer
< 23.2 V, 34.8 V, or 46.6 V
For every minute elapsed, 4 minutes is
subtracted from the timer.
Blue (flash on 2 seconds, off ½ second)
Amber (solid)
Both indicators will remain in these states as long as the battery voltage remains
above 1.91 Vpc, even if no charging is occurring. This may occur if charging is
performed by another source.