Simply Measure Method:

For 12V system, measure the input voltage from solar panel with multimeter (terminal 1, 2 of controller), it is normal if the voltage of solar panel more than battery voltage 0.5-6V. Generally, the higher input voltage, the better charge efficiency. For 24v and 48V system, the input voltage will be much more higher than battery voltage
(Note: It is normal phenomenon the controller can not find Maximum Power Point within 10 minutes from system start.)

Indicator:

1.Load indicator, green, bright indicate there is output, Load could work, " off" indicate there is not output, and Load can not work.
2.Low Voltage Indicator, red; bright indicate the voltage of the battery is low. Load could not normal working. This is normal phenomenon. When the battery voltage recover to 12.6V or (25.2v), the Load will be automatically working, at this time the indicator is off.
3.Charge Indicator, red, bright indicate the battery need to charge, flickering means float charging, off means charge has stop.

RESET Button:

Please notice the rated current of your controller, if there is short circuit or overload happened, the MPPT controller will close output. (Load indicator off, Low voltage indicator off.)
If you need the MPPT controller recover work, please check the reasons and clear out the fault firstly. Then put a small stick such as toothpick, ball-pen tip inside the RESET hole, and press RESET button will be OK.

Attention:

1.Please check the rated voltage of the solar panel, battery, and load are all the same with 12V or 24V or 48V.
2.Please pay attention to connection, do not connect the " +" " -" poles of solar panels and loads wrong.( Wrong connection will be burn your MPPT controller)
3.Battery must be connected earlier than solar panels and load. When take off the system, Solar Panels must be take down first, then cut off battery.