The solar charge controller is divided into PWM and MPPT types. This solar panel and charge controller is used in the solar power generation system to control the solar modules to charge the battery. The solar panel and charge controller is the core control part of the entire photovoltaic power supply system.
There is a practical limit though, if the solar array is too large then the power is just wasted since the charge controller is always limiting the output. A typical recommendation is to limit the solar array to 110%-125% of the maximum controller rating.
For example, 200/12 = 16.67 amps. Therefore, if you have a 200-watt solar panel, a 20-amp charging controller is suitable for safety. If we have 4 100-watt solar panels, the equation will be 400/12 = 33.33 amps, so we suggest using a 35-amp charging controller.