HQST 20 Amp PWM Solar Panel Regulator Charge Controller with LCD Display and USB Port (20A) HQST 20A Amp solar charge controller is an intelligent and multifunctional solar charge controller with a dual USB ports design to charge electronic devices. 12V/24V system voltages are automatically recognized. With temperature compensation employed, charging parameters can be automatically adjusted. A wide range of load working modes facilitate the product's application to different types of load. All of the controlling parameters can be reset flexibly to satisfy the user's particular needs. It provides a dot matrix graphic LCD screen and a human-machine interface with a key, which makes operation on the interface rather convenient. The product provides overcharge, over-discharge, overload protection, as well as short-circuit protection. Light control: When daylight begins the light source will turn off; meanwhile, the solar panels will charge the batteries. When there is no sunlight the garden light will switch on.