SMPPT Installation & Operation Manual Version 1.0
5
battery and prevents battery from leaking gas, and this can increase the
lifetime of battery.
Float Charge:
The battery is at saturation state, and the controller charges the battery at a
trickle current to make the battery voltage fixed at the settled float charging
voltage (this voltage has temperature compensation).
(3) Charge Voltage Temperature-compensated
The controller will compensate the Float charging voltage and Absorption
charging voltage by -4mV/Cell/°C based on the current battery
temperature.
For 12V battery, the compensated voltage U=(t-25)*6*(-0.004)V
For 24V battery, the compensated voltage U=(t-25)*12*(-0.004)V
(4) Discharge Control
The controller monitors the battery voltage all the time. The load will be
switched off when the voltage less than the Low Voltage Disconnect (LVD)
point, and it won’t be switched on until the voltage more than the Low
Voltage Reconnect (LVR) point.
(5) Protection against Reverse Connected Battery
Connecting the battery to the controller by reversed polarity (under the
circumstances of solar panels disconnected) will not damage the controller.
The controller will work normally after connecting with correct polarity.
(6) Protection against Reverse Connected Solar Modules
Connecting the solar modules with the controller by reserved connection
will not damage the controller. The controller will work normally after
connecting with correct polarity.
(7) Reverse Current Protection
The controller prevents reverse current from flowing into the solar modules
12.2V
Absorption
Float
Figure 2-2: Three-stage Charge
t
2h
U
Bulk
12.7V
Float
Figure 2-3: Two-stage Charge
t
U
Bulk
