Solar-powered street lights are all the rage these days and for good reason. Not only are they cost-efficient, but they also help you do your part in saving and conserving Mother Nature. Whereas, when you discover that your new solar street lights aren’t functioning properly, it can be extremely frustrating. It can be inconvenient as well as a waste of money and time. Fortunately, you can troubleshoot the problem in a few ways.  With a little troubleshooting, you should be able to get your new solar street lamps up and running in no time!   

Common problem detection on Solar Street Light 

If you’re having trouble with your solar street lights with lead acid gel battery, check the batteries first. Chances are, that’s the culprit. After determining whether the solar lights work with regular batteries, you can investigate whether the problem is with the solar panel or the rechargeable batteries. However, we don’t rule out the possibility that it’s due to solar controller failure. 

Detection of Controller  

Solar street lights will be equipped with a controller, each controller has three indicators, from left to right on behalf of the solar panel, solar battery, and light source. Generally during the day, the first indicator light flashes slowly to represent the solar panel charging, and the second indicator light is always on to represent the solar battery storing electricity. When night falls, the controller’s second and third indicator lights are always on, indicating that the battery is discharging to the light head and the street light is illuminated normally.  

Detection of Solar panel 

The solar panel plays a role in collecting solar energy, if there is a problem, it will lead to the whole solar street light can not work normally, there are two common problems, the connection line is disconnected or the positive and negative poles are reversed. In the case that the street light has been installed, the two wires of the solar panel can be touched at the access door, such as the appearance of sparks on behalf of the solar panel charging normally, just reverse the positive and negative wiring. If there is no spark, it means that it can not be charged normally, then you need to put down the light pole and repair the connection line.

Detection of the light source 

If the controller and the battery panel work normally, found that the light does not light up, still look at the controller’s indicator light situation, if the first two indicators work normally, the third indicator light appears fast flashing, which means that the positive and negative poles of the lamps connected reverse, switch down and reconnect can be, such as the lamp can be normal light, it can work normally. If the led lamp can not work normally, the problems with the light source, and you need a new light source for replacement.

Detection of broken wires

Solar streetlights use low-voltage wire, each wire is composed of multiple thin copper wires. In the installation process, there are two situations, one, the insulation layer inside the copper wire’s broken surface can not see traces, at this time, only voltage, no current through the battery in the electricity consumption, and the light source will no longer light. Second, the insulation layer is broken, the internal copper wire is not broken, the light pole conduction is caused by a short circuit, and the light source still can not normal light.

Detection of Battery  

In the case of work, the controller indicator on the battery should be always on, the appearance of three indicators flashing at the same time, means that the battery is a serious power loss. If the battery voltage is detected above 12 volts, but the voltage drops rapidly after connecting the light, it means the battery has been damaged; if there is a serious power loss, the positive and negative battery wiring will not spark when touching.

Lamps still working during the day

There are two reasons for solar street lights still working during the day.

1. the solar panel in the daytime did not charge the battery through the controller, with 1, 2 methods to detect the solar panel and controller.
2. the controller is in the process of connection errors, resulting in the positive and negative terminals being connected backward, resulting in damage to the controller components. 

Malfunction Checking Step For Integrated Solar street lights 

Before performing any maintenance on integrated solar streetlights, it is important to check for malfunctions.

Malfunction reason 1. The voltage of the battery is too low and protected
Clearing of fault:  Place the solar light under the strong sunshine, to charge the battery.

Malfunction reason 2.  Switch or battery loosely connect 
Clearing of fault:
Step 1). Uninstall the cover panel, disconnect and connect the connector between the solar panel 、 battery、LED lamp, and make sure the connection is right. If still not working, please continue step 2.

Step 2）Disconnect the battery, switch it on, and use the multimeter to check the voltage of the battery, if exist outputting voltage exists, we can judge whether the fault is the switch losing,  then please check the switch losing or not.

Malfunction reason 3. :  Unable to charge
Clearing of fault:  Place the solar panel under strong sunshine to charge the battery, and use a multimeter to measure the solar panel, if there is current from the solar panel and the voltage is normal, then judge the fault on the controller, so we need to change the controller.

Malfunction reason 4. : Another fault on the controller 
Clearing of fault:  Exchange the controller of the 5 solar lights, connecting the DC power supply to charge the battery,  if the battery can be charged,  then judge the fault on the controller.

Troubleshooting solar street lights with a lithium-ion battery 

1. Viewing the indicator lights on the controller

•  The blue light is always on (which means the battery is fully charged ) – The function is normal and fully charged
• Blue light is flashing (charging every 1 second) – normal function, it means battery is charging
• Red light is slowly flashing (battery voltage would be below 12V) – normal function
• Red light is always on (means battery is over-discharged) – the battery is not functioning properly and the battery is exhausted
• Red light blinks slowly (1 second once, load disconnected, light off) – LED function is abnormal, the light source cable is not well connected
• The Red light fast flashing (2 times per second, indicating that the load is short-circuited and the light is not on)-LED function is abnormal, and the positive and negative poles of the light source are reversed
• Traffic lights light slow flashing together (the battery is dead or the cables are not in contact or the controller is broken)
• Traffic lights light bright together ( controller error)

2. Troubleshooting methods for solar street lights

Issue A. No lighting at night, but the indicators are working

 The blue light is on.

Check if there is a strong light source around. If yes,  you need to remove the strong light or the solar street light; if you can’t remove anyone, you would need to replace the controller with a higher photovoltaic voltage.

 The red light is flashing and the load is not on.

1) Ensure that the controller is working properly. Test whether the load is working normally by connecting the normal function controller from the side to the light body. If the load is still off, the LED light source is defective. If it is normal, the controller is malfunctioning. Then you need to replace the controller.

2) Make sure the LED light source is functioning correctly. Test if the LED light source is operating normally by using an adjustable power supply at 36V / 24V / 12V (according to the light source voltage), if not, replace it with a new one.

The red light is always on and the battery is not powered.

1. If there is no sun for several days in a row, wait for the next day to charge the battery, and observe whether the lamp is charging during the day. An intermittent blue light indicates normal charging during the day. At night, the lamp will automatically light up.
2.  If you charge the battery on sunny days for a few days, and the light still does not turn on at night, it means that the solar panel or battery cannot be charged or discharged.

a. Test Solar Panel Function (please refer to B below)

b. Test battery function (please refer to B below)

c. Precautions:

(1) Write down the battery voltage value in the morning and the battery voltage value in the evening. If the voltages in the evening and morning are consistent, the battery cannot be charged.

2) The voltage of the solar panel must be measured with a multimeter by putting it in the sun, removing the junction box to check the charging voltage, or testing the voltage directly on the waterproof cable connector.

3) Testing the Voltage, and current of the solar panels; Testing the battery Voltage, and current.

Issue B.  No lighting at night, no indicator light on  

1). Check the waterproof connector. Ensure that the waterproof-to-plug is not shorted by water by unplugging the solar panel-to-plug

2). Test the function of the solar panel. Unplug the solar panel plug, open the solar panel junction box, and place it in the sun. Measure the voltage of the solar panel with a multimeter. The solar panel is normal if its voltage is higher than 16V or 32V.

3). Test the battery function. Unplug the battery cable and measure the battery voltage with a multimeter. If it is 0v, the battery is in deep protection due to long-term power loss. Use a DC power supply and adjust the voltage to 14.6 or 29.2 (lithium iron phosphate), 12.6V 25.2V (ternary lithium ), Charge and activate the battery. If the voltage is lower than 10V or 20V (lithium iron phosphate), 8v or 16V (ternary lithium), the battery is faulty, replace the battery. If the battery voltage is higher than 12.6 or 25.2 (lithium iron phosphate), 10.8 or 21.6 (ternary lithium), the battery is normal, replace the controller.

Issue C. Lighting time is too short at night

1). You should check whether there are trees, fences, electric lines, or light poles above or beside the solar street light with the potential to block the sunlight. Take down any obstruction or solar street lights that are in place.

2). Check whether the solar panels are covered by leaves, bird feces or sand, and other obstructions. If so, clean them up.

3). Check whether the installation angle of the solar panel is vertical to the noon sun. If not, adjust the installation angle of the solar panel.

3. How to release battery protection? 

Why do we need to set protection voltage? Solar streetlights are generally set with protection voltage. If we do not set the protection voltage, the battery will be vented, which will damage the battery.

Why does the battery run out?  The amount of discharge is high, but the amount of charging is small every day. In a discharged>charged state for a long period of time, the battery loses power. Batteries can run out of power if the led light is too powerful.

When the battery would be protected? The battery would be protected once it’s overcharged or over-discharged. Then the battery will not be charged and the light will not be turned on again.
How to release the battery protection?  we need to charge the battery for a few days to release the battery protection. Then the solar lamp can be working again. 

4. How to activate a protected battery

1. Charging the battery directly with an external power supply is recommended. Activate the battery by charging it with 14.6 v or 29.2 v (lithium iron phosphate), 12.6 v or 25.2 v (ternary lithium). Batteries are activated when their voltage rises from 0V to 9V. It is possible to fully charge the battery with an external power supply, or the battery can be charged with a solar panel and controller.

2. You can directly charge the battery with a solar panel if you don’t have an external power supply (you’ll need to cut the solar panel and connect it to the battery). Measure the voltage of the battery after 10 minutes. When the battery voltage reaches 9V, the battery is already activated. In order to prevent battery damage, we do not recommend charging the battery directly from solar panels.

Conclusion 

 If you are experiencing any of the problems mentioned in this blog post, don’t hesitate to reach out to us for help. We would be more than happy to troubleshoot the malfunctioning solar street light and get it up and running again as soon as possible. Have you had any experience with repairing or troubleshooting solar streetlights? Let us know in the comments below.