Product Description: Battery Temperature Sensor for Solar Charge Controllers (20' cable) Battery Temperature Sensor Improves Charge Control and Battery Performance. The battery temperature sensor allows the charge controller to continuously adjust charge voltage based on actual battery temperature. Temperature compensation of charge voltage assures that the battery receives the proper charge voltage as battery temperature changes during normal operation. Features: Compatible with all Blue Sky Energy charge controllers capable of temperature compensation Sensor element is double sealed for protection from the elements Sensor housing mounts to battery terminal to more accurately measure internal battery temperature ETL Listed To UL STD. 1741, Certified to CAN/CSA STD. E335-1/2E, CE Labeled Specifications Brand: Blue Sky Energy Length: 20ft