How to Choose a Street Light Solar Charge Controller
Solar controller is applied to photovoltaic system. Its full name is solar charge controller, which regulates and controls the operation of solar panel, storage battery and load. Solar charge controller serves as the command center of photovotaic system and ensures that the whole photovoltaic system operates effectively and safely.
Solar street light controllers are mainly applied to photovoltaic systems which are installed in the houses, commercial areas, factories and pastoral areas.
Brief Introduction
The basic functions of solar street light are as follows:
1、Overload Protection;
2、Short-circuit Protection;
3、Reverse Discharge Protection;
4、Reverse Electrode Protection;
5、Lightening Protection;
6、Under-voltage Protection;
7、Overcharge Protection;
8、Load Start-up Restore Protection;
9、MPPT.
Characteristics
1、Automatic identification of 12V/24V system voltages.
2、Effective tandem type PWM charging method: expend the lifespan of storage battery and enhance the system performance.
3、Adopts MOSFET as the electronic switch without any mechanical switches.
4、Automatic identification of day and night.
5、LED digital function menu setting.
6、The setting time frame of street light ranges from one hour to fifteen hours.
7、Unique double time frame control: enhance the flexibility of street light system.
8、With all-sided waterproof design, the controller can adapt to environment that is humid or with dust.
9、Support charging sealed batteries, gel batteries and abroach batteries.
10、Featuring a temperature compensation function, the controller can automatically adjust charging and discharging parameters, thus extending the lifespan of storage battery.
11、The controller has the function of overheat, overcharge, overdischarge, overload and short-circuit protection.
12、The reverse connection automatic protection of combination of photocell and storage battery.
Features
1、ensure the constant current output
LED light can not normally function until its current has been constant or restricted. Generally, people used to restrict the LED light’s current by adding an external power supply. However, it will bring efficiency loss. Thus, it is not a suitable method.
2、control the output time frame
Solar controller will output current and start to work in a well-setting time frame.
3、regulate the output efficiency
The brightness level of LED light can be adjusted by regulating the efficiency. For example, the efficiency of street light can be adjusted to 30W before dawn or 15W at the midnight. If doing this, the lighting needs can be realized and the budget of storage battery and solar panel can be saved. Besides, the lifespan of LED light can be significantly extended.
How to choose a solar controller
1、Users are supposed to choose solar controller with low power consumption. The controller needs to work for 24 hours without a break. The controllers with high power consumption will consume a part of energy of photovoltaic system. Thus, it’s better to choose the controllers with low power consumption of less than 1mA.
2、Users are supposed to choose solar controller with high charging efficiency. The controllers with MCT charging mode are able to automatically track the maximum current. When there is not enough sunlight or in the winter, The charging efficiency of MCT charging mode is 20% higher than other modes.
3、Users are supposed to choose solar controller with two-circuit power regulation. This kind of solar controllers have been widely popularized. When there is few walkers on the street at night, the controller will automatically shut off one circuit or two circuits to save the energy as well as regulate the efficiency according to the LED light operating status.
Users should also pay attention to the protection function of controller. The controllers with trickle charge mode can well protect the storage battery and expend the lifespan of battery. Besides, the under-voltage protection value should be over 11.1V in order to prevent the storage battery discharge.
Operating Principle
The main energy source of street light is sunlight. Street light can automatically charge in the daytime and work at night. The installation of street light is simple and convenient with no need of laying any complex and expensive cables. Besides, the layout of light can be adjusted. The street light is light-operated, save, highly-effective and energy-saving, which is fully recognized by people.
The following description is an introduction of solar street light controller which embedded with single chip. The controller can automatically identify 12V battery and 24V battery, regulate the battery and indicate the overvoltage and undervoltage status of battery. The controller adopts two-circuit load output and has the function of overcurrent and short-circuit protection. The rated current of each circuit of load can be 5A. The two-circuit load has various working modes, such as simultaneous lighting, time-sharing lighting and separate timing.
Collecting the storage battery voltage is to identify the working voltage of storage battery. The charge of storage battery is regulated by PWM function of controller. If there is open-circuit in storage battery, the controller will shut off the load to prevent it from damage when the solar panel is normally charging. When the solar panel is not charging or at night, the controller will not function because of electricity lack.
Overcharge Protection:
When the charging voltage is higher than protection voltage(15V), the controller will automatically shut off the charging to storage battery. Later when the voltage reduces to maintenance voltage(13.2V), the storage battery will be in the floating charge. When it is lower than maintenance voltage, the floating charge will be shut off and the storage battery will be in the equalizing charge. When the storage battery voltage is lower than protection voltage(11V), the controller will automatically shut off the load to protect the storage battery from damage. When using the three-stage PWM charging method, the solar panel will function at the maximum efficiency and the charging efficiency of system will be increased.
This system is designed with two-circuit load output. Both of the circuits are independently detected and controlled. And they are well protected from overcurrent and short-circuit.
Connection Method:
Generally, the solar street light controllers should be connected to light cable first, and then be connected to battery cable.Finally, the controllers are connected to solar panels.