Two-Stage Charging Process - Xantrex Freedom SW 230V 815-3524-02 Owner's Manual

NOTE:
The battery voltage can increase above the float voltage when
using an external charging device such as PV arrays, wind turbines, and
micro-hydro generators. Be sure to include appropriate charge
management equipment with all external DC sources.
Table 20 Preset Float Voltage Settings
Battery Type Preset Float Voltage
Flooded 27.0
Gel 27.6
AGM 26.8
Custom 27.0 (changeable)
975-0696-01-01

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 230V 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 (shore power) 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.
Battery Charging Reference
67