Profile: Heliotrope PV, LLC manufactures solar charge controllers for the mobile market. Our product names are HPV-22, HPV-22B, HPV-30D. Our HPV-22 charge controller has standard features such as 22 amp charging capabilities, current limit on output, selectable charge set point, liquid crystal display and battery temperature compensation. The HPV-30DR solar charge controller has standard features such as 30 amp charging capabilities, current limit on output, selectable charge set points, liquid crystal display and external voltage sensing feature.