Wagan Solar Voltage Controller 30A provides a precision charge control system to ensure the battery is properly and fully charged, resulting in enhanced battery performance with less battery maintenance. An equalize function is also included to periodically condition liquid electrolyte lead-acid batteries. A built in LCD digital display monitors solar charge performance shows battery voltage, solar panel current and output charge current. You can actually see current boost working by noting the difference between solar panel current and output charge current. A charge status LED indicates the present charge mode and shows when the battery has become fully charged. Control your energy source and protect the batteries from being overcharged. Digitally monitors solar systems up to 400 watts. Fuse protection on both battery and solar array as well as features built-in reverse blocking diode. Reverse polarity protection and low power consumption. This item is designed to protect your 12 volt GEL or lead-acid battery from being overcharged by solar panel. It provides the protection of battery reverse connection. This controller displays charging current or battery voltage from the LCD meter.