What Are the Main Functions of a Solar Controller?

Solar Controller is a device that controls the charging of batteries from solar panels and regulates the voltage for sensitive devices. It regulates and controls the charging and discharging conditions of the battery, and controls the output of the solar panel and battery to the load according to the power requirements of the load. It is the main control part of the entire solar power supply system.

What are the main functions of the solar power controller?

• Solar controller over-current and short-circuit protection

  
  

• Solar controller over-voltage protection

  
  

  It automatically shuts off the output when the voltage is too high to protect the equipment from damage.

  
  

• Solar controller lightning protection

  
  

  If lightning strikes, the varistor can prevent it and protect the controller from damage.

  
  

• Solar controller battery reverse connection protection

  
  

  If the battery's positive and negative poles are reversed, it can be corrected and continued to be used.

  
  

• Solar controller battery open circuit protection

  
  

  If the battery is open circuited, the solar power controller will limit the voltage at both ends of the load to protect it from damage. If the controller does not receive any power during the night or when the solar panel is not charging, there will be no action.

  
  

• Solar power controller overcharge protection

  
  

  When the charging voltage is higher than the protection voltage, it will automatically disconnect the battery charging. After the voltage drops to the maintenance voltage, the battery will enter the float charging state. When the voltage is lower than the recovery voltage, the float will be turned off and enter the equalization charging state.

  
  

• Solar power controller over-discharge protection

  
  

  When the battery voltage is lower than the protection voltage, the controller will automatically turn off the output to protect the battery from harm. After the battery is recharged, it will automatically resume power supply.

  
  

• Solar power controller self-checking function of solar controller

  
  

  When the controller is affected by natural factors or improper operation, it can perform self-checks to let the user know whether the controller is functioning normally, reducing unnecessary work hours.

  
  

• Solar controller recovery interval

  
  

  To prevent load work jitter caused by line resistance or battery self-recovery characteristics, the recovery interval for overcharging or over-discharge protection on the solar controller is implemented.

  
  

• Solar controller temperature compensation

  
  

  By monitoring the battery temperature, the charge and discharge values are adjusted to keep the battery in an ideal working state.

  
  

• Solar controller light control

  
  

  Mostly used in automatic lighting fixtures, the solar controller automatically turns off load output when the environment is bright enough, and automatically turns on the load when the surrounding environment dims, achieving automatic control.

Andy Cao

I’m Andy Cao, an energy engineer with over 16 years of hands-on experience in solar inverters, lithium battery energy storage, photovoltaic systems, and solar street lighting. I focus on real-world system performance and write to share practical, experience-based insights for professionals working in the solar energy industry.