In the Orion-Tr Isolated DC-DC Chargers the remote on/off circuit is referenced to the primary battery (e.g. starter battery). The Orion-Tr DC-DC Charger Isolated remote cable is intended for applications where the remote on/off signal is referenced to the secondary battery (e.g. lithium battery with BMS).
SKU: ASS070300100What is the difference between isolated and non-isolated? The isolated version has a separate, galvanically isolated input and output NEG while the non-isolated uses a common negative return. If both your source and target batteries share a negative return (ie chassis ground) then you do not need the isolated version.