Solar Charge Controller (or Regulator) is a device which protects the batteries in a solar electric system from being overcharged or being over-discharged. It is needed in virtually all solar power systems that utilize batteries. With the development of technology, controller has more additional functions now, such as load control function, LCD display, hybrid system controllers, etc.
Electronic protection:
PV Array Short Circuit, PV Overvoltage , PV Overcurrent ,  Load Overload , Load short circuit, PV Reverse Polarity, Battery Reverse Polarity, High Voltage Transients.
*MPPT charger controller (Maximum Power Point Tracking) can make the solar module operate at ideal voltage which the solar modules can product the maximum available power, it will increase the solar charging efficiency by 10 to 30%