Docooler 30A 12/24V Solar Panel Battery Charge Controller Regulator Light&Timer Control Temperature Compensation PWM Type of Charging (Automatic Lighting Control + Time Functions) Intelligent control by single chip and professional software. Full auto protection against over-charge, over-discharge, short-circuit, over-load and reverse connection. Series connection PWM circuit, more effective charging. High precision temperature compensation with external temperature sensor. Able to work normally under low & high temperature and humid environment.