There are two main types of solar controllers (also known as solar charge controllers) on the market: MPPT solar controllers and PWM solar controllers.
PWM-Pulse Width Modulation Type Solar Controller: It is a current control type that will switch the input current of the PV array in PWM pulse mode. As the battery tends to be full, the pulse width shortens.

MPPT - Maximum Power Tracking Solar Controller. Multiply the voltage U and the current I of the solar cell to obtain the power P, and then judge whether the output power of the solar cell reaches the maximum at this time. If it is not running at the maximum power point, adjust the pulse width, modulate the output duty cycle D, change the charging current, and perform real-time sampling again to determine whether to change the duty cycle. This optimization process ensures that the solar cells always operate at the maximum power point to fully utilize the output energy of the solar cell array.

MPPT can increase the power generation of solar modules and utilize the power of solar modules with maximum efficiency; it can increase the power generation by 20-30% compared with PWM controllers. The choice of these two controllers depends on personal needs.