The SunGuard can be tested for correct operation as follows:
Wire the SunGuard into your system with Solar and Battery attached to the appropriate leads
Measure battery voltage
Measure solar voltage
If the battery is charging up (has NOT reached regulation voltage) the solar voltage and battery voltage will be about the same. If the battery is fully charged, the battery voltage will be at 14.1V* and the solar voltage will be higher. If solar voltage is greater than battery voltage and the battery is not yet fully charged, there may be a problem with your SunGuard.
* The 14.1V regulation voltage setpoint is temperature compensated. If the ambient temperature is warmer than 25C (~78F) the regulation setpoint will be lower. The regulation setpoint will be higher in colder temperatures.
NOTE: Measuring the SunGuard battery voltage leads without the battery attached is not a valid test!