1. Always keep the battery on fill voltage condition.2. Prevent the battery from over-charging.3. Prevent the battery from over-discharging.4. Prevent the battery from reverse charging to solar panels during nights.5. Reverse Polarity Protection for Battery6. Reverse Polarity Protection for Solar Panels7. When the battery voltage is low, the controller will automatically cut off the load from the system. If the voltage of battery is back to normal and the load will restart working.8. Thunder protection9. According to the battery voltage grade, the controller can automatically set charge-off voltage, the load-off voltage, the load- voltage. (The parameter is default under 25 condition, locked by the CPU procedure, cannot adjust.)10. The controller will automatically compensate the temperature of the charging voltage according to the changes of temperature.Colour:blueMaterial:ABStype:30APackage Contents:1 x Solar Panels Battery Charge Controller1 x Chinese and English manualOnly the above package content, other products are not included.Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.