Victron Argofet 100-2 100A FET battery isolator for 2 batteries

Argofet 100-2 Two batteries 100A by Victron

Similar to isolation diodes, FET isolators allow two or more batteries to be charged simultaneously by a generator or through a charger connection without connecting the batteries to each other. Discharging the onboard electrical system battery does not lead to the simultaneous discharge of the starter battery.

Unlike isolation diodes, FET isolators have virtually no voltage loss. The voltage drop is less than 0.02 volts at low currents and only 0.1 volts at higher currents.

With ARGO FET battery separation, no voltage increase is required. However, short cable lengths and sufficient cross-sections should be ensured.

An example:
A 100 A current has a voltage loss of 0.26 volts with a cable length of 10 m and a cable cross-section of 50 mm2. With a 5 m cable with 10 mm2, a 50 A current causes a voltage loss of 0.35 volts!

Generator starting excitation
Some generator types require direct current at the B+ terminal for starting excitation. On the one hand, there is a direct cable connection between the battery and the generator. On the other hand, however, the isolation diode prevents reverse current flow, so that the generator does not start. The new Argofet battery separator has a special current-limited connection for starting excitation when the generator is started.