Features Solar Charging: This MPPT solar charger board allows you to transfer the power from solar panels or other photovoltaic devices to rechargeable batteries. 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. Better Management: Equipped with maximum power point tracking function for solar panels, providing complete charging management for single lithium batteries. Stable Operation: The constant current charging current is set by an external resistor. Trickle charging of deep discharge batteries. Automatic charging function. The Parameter: Charging current up to 2A. 300KHz PWM switching frequency. Constant voltage charging voltage of 4.2V ± 1%. Specification: Item Type: Solar Charging Module Material: PCB Input Voltage: Select the corresponding 12V module based on the nominal voltage of the solar panel.  Output Voltage: 3.7V nominal, 4.2V full stop voltage, for single series lithium battery charging management.  Interface: 2Pin PH2.0/JST Features:  1. Maximum power point tracking function of solar panels.  2. Complete charging management for a single lithium battery.  3. Charging current up to 2A.  4. PWM Switching Frequency: 300KHz.  5. Constant Voltage Charging Voltage: 4.2V ± 1%.  6. The constant current charging current is set by an external resistor.  7. Trickle charging of deeply discharged batteries.  8. Automatic recharge function.  9. Indication of charging status and charging end status.  Package List: 1 x Solar Charging Module 2 x Connecting Cable Package List 1 x Solar Charging Module 2 x Connecting Cable