Among solar products, LED solar lights are one of the most prominent ones. They are used for several purposes, and they frequently come with solar controllers. So the controller is one of the essential parts of the solar lamp after the lithium battery.
This solar controller acts as the beating heart of the solar power system. It is used to switch on and off the lighting and charging of solar LED lights. It is also used to operate the dark to dawn dim, motion dim, time control dim, and battery charging controls. These smart controllers also regulate the solar battery to avoid being overcharged or undercharged.
Solar light controllers can also be classified differently according to different categories of solar-powered led lamps. With all these types, sometimes selecting the right one is a bit challenging. So, how will you choose solar light controllers to match your outdoor solar lighting project? Are you already aware of the solar controllers’ main parameters based on each different project’s requirements? Do you know how to set them? If not yet, then please continue reading. We, ADN will unravel all the secrets about the solar lamp controllers for you one by one.
You Need to Know Each of its Functions
Functions： Dark to Dawn, Time Control Dim, Motion Dim
These are the main function of a solar LED lights controller. ADN already provided a detailed introduction of these three functions on the solar street light product page.
APP monitoring + GPS
This function can monitor and set the solar street light battery, solar panel, and LED light parameters in real-time. You can access the data on APP or computer. If GPS is built in, you can also monitor the location of solar streetlights in real time. If the solar street light is stolen, you can check the GPS to retrieve the stolen solar light.
Why is the Solar Light Prone to Damage?
If you will look at the circuit diagram of solar-led road lights, you will find that the battery, solar panel, and LED are all connected to the controller. The controller is like the brain center of solar LED lights. It controls the normal operation of the three components: battery, solar panel, and led. So if there is a problem with the controller, the whole solar led lamps will not work properly.
In addition, the controller needs to implement many functions and needs to make corresponding control according to the changes in different external environments.
Dark to Dawn Dim: Solar panels output different voltages for the intensity of light. The controller can adjust the LED on/off according to the output voltage of the solar panel.
Motion Dim: Sensors (human sensors or radar sensors) are also connected to the controller. In the sensing state, the inductor changes the output voltage. The controller can adjust the power of the LED according to the voltage change. This is the principle of induction dimming of solar lamps.
Battery Protection During Charging: It acts as overcharge, high voltage, low voltage protection, etc. These functions require the controller to monitor the voltage and current of the battery and the voltage. It also regulates the current of the solar panel in real-time, then makes different adjustments based on the received data. Also, the following protection functions are also required to ensure the long-term operation of various accessories of solar street lights:
- To protect the battery reverses the connection.
- To protect the solar panel reverse connection.
- To prevent the battery discharge to the solar panel at night.
- To protect the battery reconnect the voltage.
- The LED output is short and has open circuit protection.
All of the above functions require the precise control of the solar controller. This is to ensure that the solar lighting system can work for a long time in various environments. So in the first few years, the controller has been the component that limited the quality and life of solar street lights. (In fact, many solar power generation system controllers are only guaranteed for 1 to 2 years. However, the hardware requirements and voltage of the solar system controllers are also substantially higher than those of the solar street light controllers.)
Due to the application of hundreds of thousands of outdoor solar light projects, engineers continued to optimize the system and hardware design. This is to cater for the event of failure. Now, the quality of solar controllers has been very stable. However, to ensure quality, ADN recommends not choosing an underpriced controller supplier.
The solar controller can be divided into 3.2v and 12V/24V according to the voltage. Mostly, you can only apply the 3.2V controller to low-power solar street lights, and the maximum LED power is usually within 20-25W. The cost of the 3.2V controller is also much lower than that of the 12V/24V controller.
Based on the type of technology, it can be divided into MPPT & PWM
PWM-Pulse Width Modulation Type Solar Controller
It is a current control type that will switch the input current of the PV array in PWM pulse mode. As the battery tends to be full, the pulse width shortens.
MPPT – Maximum Power Tracking Solar Controller
(Click to check more about MPPT solar charge controller.)
To obtain the power P multiply the voltage U and the current I of the solar cell. Then judge whether the output power of the solar cell reaches the maximum at this time. If it is not running at the maximum power point, adjust the pulse width, and modulate the output duty cycle D. After that, change the charging current and perform real-time sampling again to determine whether to change the duty cycle. This optimization process ensures that the solar cells always operate at the maximum power point to fully utilize the solar cell’s output energy.
When the ambient temperature is not low, the charging efficiency of PWM and MPPT is similar. However, when the ambient temperature is too low, the charging efficiency of PWM will be much lower than that of MPPT. But the cost of the PWM controller is much lower than that of the MPPT controller. Therefore, there is no need to use MPPT controllers in countries close to the equator, such as Saudi Arabia, the Philippines, Malaysia, Africa, etc.
7 Important Solar StreetLight Controller Parameters
Understanding the parameters of the solar light controller can help you design solar streetlights. The picture below is a screenshot of the parameters of one of our MPPT solar street light controllers. You can use it as a guide if you want.
- System voltage: 12/24V The battery pack voltage distinguishes the voltage.
- Battery C.V charge: This voltage is the voltage after the battery is fully charged. When the battery voltage reaches this voltage, the system will automatically terminate the charging of the battery.
- Float Charge: Float charge voltage is used to continue charging to supplement the self-discharge of the battery when it is about to be fully charged.
- Low voltage disconnect voltage: When the battery voltage is lower than this voltage, the system automatically disconnects the battery to protect it from deep discharge.
- Max panel Power: When selecting the solar panel power, the solar panel should not exceed the maximum power allowed by the system.
- Lighting off: This parameter is the output voltage threshold of the solar panel controlling the dark to dawn dimming of the LED light.
- LED output current range voltage range, max output power: These parameters indicate that you should pay attention to selecting the LED PCB that matches the controller.
How to Set Up the Solar Light Controller
Usually, we need to do the following settings for the controller
LED: We need to know the series and parallel situation of LED chips in PCB. In this way, you can determine the input voltage of the PCB board. Then based on the LED power, the input current of the LED is obtained.
Solar Panel: We need to find the power and voltage of the solar panel for this one.
Battery: We need to find the type of battery: Is it a gel battery, LiFePO4 lithium battery, or LiMN2O4 lithium battery? Aside from that, we should also know the voltage of the battery, is it 3,12 or 24v. For more battery voltage and current settings, the controller factory will do the factory settings according to the battery type and voltage. Click to learn solar lights battery knowledge.
Dimming Way: It regulates light control, time control, or a combination of light control and time control. It also monitors the power percentage of the lead in the non-inductive state and the percentage each time.
If we go into specific production details, we also need to confirm the length of the wires connecting the controller to the LED, battery, sensor head, and solar panel, the size of the sensor head, and so on. Click to see more details of solar street light production processes.