58 Freedom SW Owner’s Guide
Battery Charging Reference
This section describes the multistage charging algorithm (formula) of the
Freedom SW.
Battery Types
Freedom SW charges flooded (or wet) lead-acid, Gel, AGM (absorbed
glass mat), and custom batteries.
• Flooded (or wet) batteries have removable battery caps for refilling
with distilled water and testing the electrolyte.
• Gel batteries have the electrolyte in the form of a gel rather than a
liquid and do not require topping up. Gel batteries are sealed and the
battery caps are not removable.
• AGM (Absorbed Glass Mat) batteries are similar to gel batteries
except that the electrolyte is absorbed into a fiberglass matting.
• Custom battery is configured by the dealer, factory, or service center
for battery types other than those listed above.
Charge Algorithm Stages
Three-Stage charging
If three-stage charging is enabled, the Freedom SW will charge batteries in
a sequence known as three-stage charging. Whenever qualified AC power
is present at the inverter’s input, it passes power through to the connected
load and begins charging the batteries. The charging voltage delivered to
the battery depends on the battery’s:
• type setting
• temperature (by switch setting or battery temperature sensor)
• state of charge
The three automatic stages are:
• bulk
• absorption
•float
See Figure 32 for a graph of the three-stage charging profile.
There is a fourth stage, equalization, which is initialized manually as it is
only performed occasionally and only on flooded (or wet) batteries.
RISK OF BATTERY DAMAGE
Since the Freedom SW can only select one battery type setting for all
batteries connected to its bank, do not mix battery types. All connected
batteries should either be: Flooded (or wet) or Gel or AGM or Custom.
Failure to follow these instructions can damage the unit and/or
damage other equipment.
Freedom SW 3K2K InvChg Owners Guide.book Page 58 Wednesday, October 9, 2013 1:34 PM
