Xantrex Freedom SW Series, Owner'S Manual, Page: 95 / 122

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Battery Charging Reference
Two-Stage Charging Process
Two-stage (or no float) mode differs from an ordinary three-
stage charge mode in that it does not continuously maintain
the battery at float voltage. Instead, the Freedom SW begins
charging the battery in bulk mode whenever the battery
voltage drops below the recharge level. While the battery
voltage is above the recharge level the inverter’s AC transfer
switch continues to pass power through from the utility grid
to the loads, but does not actively charge the batteries.
Two-stage mode increases efficiency of utility connected
systems by reducing the amount of power consumed by the
inverter and batteries compared to when the battery is
continuously maintained at
Float Voltage
. This feature can
extend the life of most batteries.
NOTE:
If the AC input fails or drops below the lower VAC limit (as set in
AC Settings
), the complete multistage charge cycle (bulk, absorption,
float/no float) restarts once the source AC recovers to within the
acceptable range. If the batteries are already nearly full, the charge cycle
will take little time to complete. Figure 36 Two-Stage Charging Cycle
FSW Owners Guide.book Page 81 Tuesday, August 7, 2018 9:03 AM