Xantrex Freedom SW 815-2024, Руководство пользователя

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97-0019-01-01 61
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 multi-stage 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 33 Two-Stage Charging Cycle
Time
Time
Absorption Voltage
Max Absorb Time - Dflt 3 hrs
(adjustable 1 min - 8 hrs )
2-Stage Charge
Absorption Stage
Bulk Stage
Recharge
Voltage
Battery
Voltage
Battery
Current
Max Charge
Rate
Return to
Bulk Stage
Absorption Exit Current
Threshold = 2% of
programmed AH capacity
Freedom SW 3K2K InvChg Owners Guide.book Page 61 Wednesday, October 9, 2013 1:34 PM