I. Controller shows no alarm but is not charging;

Possible causes:

1) Battery is fully charged; controller is in standby mode.

2) Incorrect battery type selection or incorrect charging parameters.

3) PV input voltage is lower than the controller's startup voltage.

4) Controller malfunction.

Troubleshooting steps:

1) Verify that the battery type selected on the controller matches the actual battery type.

2) Confirm whether the battery voltage displayed on the controller has reached the saturation voltage and if the battery is fully charged.

3) Use a multimeter to measure the PV input voltage; check if it matches the PV voltage displayed on the controller and exceeds the controller's charging startup voltage.

II. Controller does not turn on; screen is blank:

Possible causes:

1) Battery and PV connections are loose or reversed;

2) Battery voltage and PV voltage are too low;

3) Controller is damaged or malfunctioning.

Troubleshooting steps:

1) Check the wiring at the controller's BAT and PV terminals for loose or incorrect connections.

2) Use a multimeter to measure the voltage at the BAT and PV terminals; verify that the BAT and PV voltages meet the controller's supported voltage specifications.

3) If the conditions above are met but the screen remains blank, the controller is likely faulty.

III. Controller shows a red light; device alarm triggered:

Possible causes:

1) Battery and PV cables are loose or incorrectly connected;

2) Battery voltage or PV voltage is too high or too low;

3) Incorrect battery system parameter selection;

4) Controller is damaged or malfunctioning.

Troubleshooting steps:

1) Check the wiring at the controller's BAT and PV terminals for loose or incorrect connections.

2) Measure the battery and PV voltages to ensure they match the values displayed on the screen and fall within the safe operating range (i.e., not exceeding over-voltage protection limits or dropping below under-voltage limits).

3) Verify that the battery system and type selected on the controller match the actual connected battery system and type.

IV. No output voltage at the load output terminal:

Possible causes:

1) Controller load setting is not enabled;

2) Incorrect load wiring connections;

3) Battery is in an over-voltage or under-voltage state;

4) Controller is damaged;

Troubleshooting methods:

1) Set the controller load to "always-on" mode and measure whether there is voltage output at the load terminal.

2) Check the load terminal wiring for reverse polarity or short circuits.

3) Check the battery voltage status displayed on the controller to see if it is in an over-voltage or under-voltage state.

4) If the controller is damaged, contact the manufacturer for assistance.

V. Displayed values do not match actual measured values:

Possible causes:

1) Minor sampling deviation; this is normal sampling error.

2) Sampling has not been calibrated for a long time, resulting in deviation;

3) Loose sampling wire;

4) Controller sampling circuit is damaged;

Troubleshooting methods:

1) If the difference between the displayed value and the actual measured value is small, it is a normal phenomenon (sampling error).

2) If the difference is significant but the displayed value fluctuates correctly (rising or falling) in sync with the actual value, use the host computer software to calibrate the displayed value.

3) Check if the screen ribbon cable is loose; unplug and reconnect the controller display cable.

4) If the controller is damaged, contact the manufacturer for assistance.

VI. Input voltage drops to a level close to the battery voltage; no charging occurs:

Possible causes:

1) Weak photovoltaic (PV) energy;

2) PV input voltage is close to the battery voltage;

3) Controller is damaged;

Troubleshooting methods:

1) Observe whether the phenomenon persists on a sunny day.

2) Increase the PV voltage; the PV voltage needs to be at least 5V higher than the battery voltage.

3) If the controller is damaged, contact the manufacturer for assistance.

VII. Controller cannot connect to the host computer:

Possible causes:

1) Incorrect connection settings;

2) Software not run as administrator or host computer drivers not installed;

3) Damaged computer port or connection cable; 4) Controller communication circuit damaged.

Troubleshooting methods:

1) Check if the COM port number, baud rate, and address bits are correct.

2) Reinstall the host computer drivers, run the software as an administrator, and test the connection again. 3) Try connecting using a different computer port or data cable.

4) If the controller's communication function is damaged, contact the manufacturer for assistance.