Charge regulators (also called charge controllers) are the electronic gadgets used to protect the storage batteries from being over charged or over discharged.
• The basic function of the charge regulator (CR) is to disconnect the module or array from the battery when the battery is charged to a pre-set level and disconnect the load (which is connected to the battery) when the battery is discharged to the pre-set level.
• The PWM charge controller is a good low cost solution for small systems, when solar cell temperature is moderate to high (between 45°C and 75°C). Generally we use PWM type in normal solar home system.
• To fully exploit the potential of the MPPT controller, the array voltage should be substantially higher than the battery voltage. The MPPT controller is the solution of choice for higher power systems. MPPT charge controllers are very expensive compared to PWM.