TriStar MPPT Installation and Operation Manual

37TriStar MPPT Operator’s Manual
Absorption Extension
1:00 2:00 3:00 4:00 5:00 6:00
12.50 V
Bulk
Extended
Absorption
FloatAbsorption
Absorption Extension Voltage
time (hrs)
Figure4-3.Absorptionextensionchargingprole.
If battery voltage discharges below 12.50 Volts (25.00 Volts @ 24 V, 50 Volts @ 48 V) the previ-
ousnight,Absorptionchargingwillbeextendedonthenextchargecycleasshowningure4-3
above. 30 minutes will be added to the normal Absorption duration.
Float Time-out
Figure4-4.Floatexittime-outchargingprole
After entering Float stage, the controller will only exit Float if the battery voltage remains below
Floatvoltagefor60cumulativeminutes.Ingure4-4,asystemloadturnsonat4:00hrswhen
the controller is in Float stage, runs for one hour, and turns off at 5:00 hrs. The load current draw
is larger than the charge current, causing battery voltage to drop below Float voltage for 60 min-
utes. After the load turns off, the controller returns to Bulk charging and then Absorption stage
once again. In this example, a load runs continuously for 60 min. However, because the Float
exit timer is cumulative, multiple momentary load events that pull the battery voltage below Float
voltage for a combined 60 minutes duration will also force an exit from Float stage.