Victron 120a 2-battery Isolator - Diode Battery Isolators allow two or more battery banks to be charged simultaneously using just one alternator and without connecting the batteries to each other. Even when discharged, the service batteries will remain isolated from the starter batteries.Argo battery isolators have a low voltage drop due to the use of Schottky diodes: at low current the voltage drop is approx. 0.3 V and at nominal load approx. 0.45V. All models are equipped with a compensation diode, which allows the alternator output voltage to be slightly increased to compensate for the voltage drop across the isolator diodes.When installing an isolator diode, please consult a technician or our ‘Energy Unlimited’ manual.The installation of the isolator may cause a reduction in charging voltage and batteries may age prematurely. Alternator input: Some alternators require a DC voltage at the B+ output to start charging. Obviously, the voltage will be present from the moment the alternator is connected directly to a battery. Inserting a diode or FET splitter will prevent a voltage/current return from the battery to the B+ output, thus preventing the alternator from starting. The new ‘AC’ diode isolators have a limited current input that will supply the B+ output when the engine start/stop switch is closed
