Solar charge controller is basically a current and voltage controller that is used for charging the batteries and prevents the electric cells from overcharging. The range of the controller should be from 4.5A to 80A. It is mainly designed to perform two things in the solar power system i.e. charging of batteries are optimized by solar panel and prevents the electricity of the batteries while going through solar panels in the absence of sunlight. There are different types of solar charge controller but the MPPT solar charge controller is considered as the sparkling star of today. 

Features: It reduces maintenance of the system and increases the life of the battery.

1. It protects the battery from overcharging. 
2. It provides high reliability.
3. It monitors the reverse flow of the current.
4. 10amp to 40amp of charging current.

Types:

1. Simple 1 and 2 controls: It consists of shunt transistors that control its voltage in one or two steps. In this solar panel can get short-circuit if the voltage reaches a certain level. 
2. Pulse width modulated: It is used to establish a direct connection in between battery bank and solar array. It is used to send pulses of short charging series to the battery. Therefore, it is best for the solar-power systems that need small off-grid having low powers and voltage. The controller decides in what time it will send the pulses as it depends upon the current charge of the battery. It will send short pulses if the battery is fully charged and long and constant pulses if the battery is discharged.
3. Maximum power point tracking: It identifies the best working amperage and voltage that is exhibited in solar panel and matches it with the bank of electric cell. MPPT charge controller outcome is 10-30% more than other types of controllers. To provide maximum charge to the battery this controller converts generated voltage into optimal voltage. The aim of this controller is to achieve maximum power from solar-array.