What is a solar controller?
A solar controller is used in a solar power system. It regulates and controls the charging and discharging conditions of the battery, and controls the electrical output of the solar cell module and the battery to the load according to the power demand of the load, and is the core control part of the entire PV power supply system.
Role of solar controller
The basic function of the solar controller is to control the battery voltage and open the circuit, and stop the battery charging when the battery voltage rises to a certain level.
In simple terms, the solar controller can do three things:
1. Power regulation function.
2. Communication function: simple instruction function and protocol communication function, such as RS485 Ethernet, wireless and other forms of background management.
3. Perfect protection function: electrical protection, reverse connection protection, short-circuit protection, over-current protection, over-charge protection, over-discharge protection, etc.
Types of solar controllers
The popular solar controllers on the market are mainly ordinary solar controllers, PWM solar controllers, and MPPT solar controllers.
Ordinary solar controllers work by hooking up the output of the solar panel directly to the battery port and disconnecting it when the battery is full. Because of the internal resistance of the battery, it is difficult to fill the battery. The charging conversion efficiency is only 70-76%.
PWM means pulse width modulation. PWM solar controller uses the digital output of the microprocessor to control the analog circuit, which is a method of digital coding of the analog signal electricity. Controlling the analog circuitry digitally can significantly reduce the cost and power consumption of the system. The charging conversion efficiency is 75-80%.
MPPT, Maximum Power Point Tracking, means maximum power tracking. MPPT solar controller can detect the power generation voltage of solar panels in real-time and track the highest voltage and current value (VI) to make the system charge the battery with maximum power output. 99% MPPT tracking efficiency. The MPPT tracking efficiency is 99%, and the whole system can be up to 97% efficient.
How to pair controller and solar panel
The main reference is the power and output voltage of the solar panel. For example, for a 60W, 12V panel, the controller can choose 5A. The voltage of the solar panel is generally higher when it is unloaded, and the voltage here refers to the voltage of the battery.
Therefore, the power and voltage of the solar panel determine what size controller you should choose.
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