Specifications

14
If you would like to change either set point, please use one of the following procedures.
Use a Small screwdriver; an oversized tool may damage the potentiometers!
Method 1: If you own a variable voltage power supply and would like to calibrate the unit on the bench or
while it is disconnected from the main system, then the following procedure is recommended.
Connect the positive lead from your power supply to both the Battery + and Solar/Diversion terminals of the
charge controller (You will need a small jumper to go from the battery+ to the Solar/Diversion terminals).
Connect the ground lead from your power supply to one of the ground terminals of the controller.
1) Turn the float or bulk level potentiometer fully counter clockwise (calibrate one at time)
2) Set the voltage of the power supply to the desired trip point (for instance 14.2 volts)
3) Slowly turn the potentiometer clockwise until the red LED is illuminated
4) Increase the voltage of the power supply slightly and the red LED should go off
5) Slowly turn the voltage of the power supply up and down near your set point, checking to see if you
achieved your desired setting
If you do not own a variable voltage power supply, or would rather set the controller while it is installed, then
there are three additional calibration options:
Method 2: If you have an inverter that is able to set the exact float or bulk charge voltage of the battery bank to
a particular level, use the inverter as your variable voltage supply and follow the instructions in method 1 to
calibrate your set points.
Method 3: Using a volt/ohm meter to measure the exact position of the float or bulk potentiometers.
Please take a look at the figure on the preceding page, PCB set point adjustments. If you look just to the left of
either of the two blue potentiometers (pots), you will see there is a small blue circle and hole on the PCB itself.
These are meter test probe points (The drawing above has indicated them using a light blue circles drawn
around the test probe test points). If you measure the voltage at either of these trip points, you will see a reading
between 0 and 5 volts, with 2.5 volts being exactly midway. These voltages are what the microprocessor itself
uses to determine the set points you have chosen. The math used is quite simple.
The float setting of the controller can range from 12.5 to 14.5 volts (a 2 volt span). The float potentiometer
output can range from 0-5 volts (a 5 volt span).
0 volts on the float pot (0%), equals 12.5 volts float setting (0%), and 5V (100%) on the pot, equals 14.5 volts
(100%). 2.5 volts on the pot (50%) equals 13.5v (50%).
The exact formula is:
(Desired set point – Lowest set point) / 2 * 5
To set your float to say 14 volts:
(14 – 12.5) / 2 * 5 = 3.75 volts – You would set the float potentiometer to 3.75 volts (as read with the volt/ohm
meter at the test probe location) – This will result in the float setting for the controller to be at exactly 14 volts.