Advanced Battery Charging (Abc); Charging Steps - Outback FXR2012A Operator's Manual

Advanced Battery Charging (ABC)

Advanced battery technologies such as lithium-ion and sodium-sulfur may require very different settings
from the inverter's defaults or the three-stage cycle in general. The Charging Steps section describes the
individual selections and behavior. All charger settings are adjustable for different priorities. For example,
the Float voltage could be set higher than the Absorption voltage, or a step could be completely skipped.

Charging Steps

The following items describe the operation and intended use for each individual charging step as
shown in the graphs. Note that some charging cycles may not follow this exact sequence. These
include cycles which were previously interrupted, and also customized charging. Each step describes
how to defeat or customize the step if specialized charging (ABC) is required.
See page 37 for a description of multiple cycles when the charger is restarted after completion.
This page also describes multiple cycles when the charger is restarted after being interrupted.
For multiple inverters:
The charging of stacked inverters is synchronized and is governed by the master. The charger settings
of all other inverters are ignored. Slave and subphase master inverters use the master settings.
No Charging
If the inverter is not charging, several conditions may apply:

The unit is not connected to a qualified AC source. If a generator is present, it may not be running.

The unit is connected to an AC source but the charger has been turned off.
Bulk Stage
This is the first stage in the three-stage charge cycle. It is a constant-current stage which drives the
battery voltage up. This stage typically leaves the batteries at 75% to 90% of their capacity,
depending on the battery type, the exact charger setting, and other conditions.
Voltage Used: Absorb Voltage setting.
Default Set Point (nominal voltage): 14.4 Vdc (12-volt), 28.8 Vdc (24-volt), 57.6 Vdc (48-volt)
The initial DC current may be as high as the charger's maximum current, depending on conditions.
The current will begin at a high level, but will tend to drop slightly as the voltage rises. This is not a
reduction in charging. It can be viewed as a wattage "tradeoff". The actual kilowatts used by the
charger are shown in the Inverter menu. The reading is usually consistent at this stage. (See page 55.)
To skip this step: Setting Absorb Voltage equal to Float Voltage causes the charger to proceed
through the normal three-stage cycle, but at a single voltage. Setting Absorb Time to 0 causes the
charger to skip both the Bulk and Absorption stages and proceed directly to the constant-current
Refloat stage. This may not be desired if the intent is to include the Bulk stage but skip Absorption.
Absorption Stage
This is the second stage of charging. It is a constant-voltage stage. Current varies as needed to
maintain the voltage, but will typically decrease to a very low number over time. This leaves the
batteries at essentially 100% of capacity.
Voltage Used: Absorb Voltage setting. This setting is also used by Offset when in this stage. (See
page 42.) For the three-stage cycle to proceed normally, this setting should be kept higher than the
Float Voltage and Re-Bulk Voltage settings.
900-0167-01-00 Rev A
Operation
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