1. battery charger for solar powered system. Power supply voltage DC 4.4-6V, charging output voltage DC 4.2V. 2. Maximum charging current/output current is 1A, you can change the current by changing the value of the R1 resistor. Automatically adjust the charging current according to the output capacity of the input power supply. 3. Precharge adjustment for restoring deep discharge batteries and minimize heat dissipation at the initial charging stage. Constant current/constant voltage operation with thermal regulation maximizes charging rate without overheating . 4. Automatic low power sleep mode when the input power voltage is removed. C/10 charge termination. 5. Automatic recharge. Battery overvoltage protection. Item Type: Battery Solar Charge Module LED Indicator: '''' LED is charge status indicator; ''OK'' LED is OR constant voltage mode Instruction: The adaptive unit on the module can adjust charging current automatically based on the output capability of input power supply, so it is for the solar-powered , or the applications that need to charge - battery or battery with an input power supply whose output capability is limited. If your solar panel is 5V, then you can use it directly. Of course, the module can also be powered by a 5V DC power supply. Material:plastic colour:blue Package Contents: 1 x MPPT Solar Controller Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.