1、Solar Charging: This MPPT solar charger board allows you to transfer the power from solar panels or other photovoltaic devices to rechargeable batteries. 2、Convenient to Use: Insert the solar panel into one side of the solar charger, and then insert the battery into the other side to start charging. 3、Better Management: Equipped with maximum power point tracking function for solar panels, providing complete charging management for single lithium batteries. 4、Stable Operation: The constant current charging current is set by an external resistor. Trickle charging of deep discharge batteries. Automatic charging function. 5、The Parameter: Charging current up to 2A. 300KHz PWM switching frequency. Constant voltage charging voltage of 4.2V ± 1%.