Filter
Top Products
Operation
18 900-0112-01-00 Rev A
Battery Charging
IMPORTANT:
Battery charger settings need to be correct for a given battery type. Always follow
battery manufacturer recommendations. Making incorrect settings, or leaving them at
factory default settings, may cause the batteries to be undercharged or overcharged.
Figure 4 Charging Stages Over Time
All voltages in this section are given for a 12-volt system. For higher-voltage systems, the voltage can
be multiplied by the appropriate amount. (Factory defaults for each inverter voltage are shown
beginning on page 43.) Set points can be adjusted using the system display (see the appropriate
manual).
The inverter uses a “three-stage” battery charging process. The three stages are Bulk, Absorption, and
Float. These stages follow a series of steps, which are marked on the chart above. The points where
the dark line intersects the vertical dotted line indicate a change from one step to the next. The points
where they also intersect with a horizontal dotted line indicate that the charger has switched to a new
target voltage. The process shown here also includes the step of selling power back to the utility, as
this is integrally tied with the battery charger.
The Target Points and Time Limits cited under various steps are settable using the system display.
No Charging
If the inverter is not charging, any of the following conditions may apply:
The unit is inverting or not connected to an AC source.
The unit is connected to an AC source but is in a mode or stage that does not use the charger. (Silent
mode is one example.)
The unit is connected to an AC source but the charger has been turned off.
Bulk Stage
This stage activates the charger. 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% – 90% of their capacity, depending on conditions.
Target point:
Absorption Voltage
setting. The default setting is 14.4 Vdc (in a 12-volt system).
Bul
k
Absorption
Sell RE
Silent
Float Timer
Silent Float
Sell RE
Absor
p
tion Set Point
Sell RE Set Point
Float Set Point
Refloat Set Point
Voltage
Time
No
Charge