12V/24V 20A solar charge controller LCD Display SR20 Charge controllers are vital components in battery-based PV systems, keeping the PV array from overcharging the batteries and optimizing charge current. Winiversal solar controller is superior in quality and compatible with most types of solar inverters. SR20 charge controller has all-around protecting functions for better charging the battery and protecting electrical devices. The mutual operation feature helps user regulate the charging current, charge-off voltage, etc. The efficiency is 30% more than early-developed charge controllers.