Solar controller Versions available: 20, 30amp 12/24 volt auto-work negative or positive ground Microprocessor which is made in usa Pwm or on/off series battery charging options State of charge (soc) battery regulation Battery ah setting, boost charging, equalising charging, float charging Automatic load reconnection, manual load switch Automatic selection of voltage (12 v / 24 v) Temperature compensation Lcd display: soc as a fuel gauge, all system parameters in digital value, system status as symbols Full circuit protection, electronic fuse � field adjustable parameters by four buttons Load control option: on/off, dusk-to-dawn, on + setting hours, setting time on/off. (for type �ii) Real clock display 20pcs/carton