Victron Energy's Argofet Isolators allow simultaneous charging of two or more batteries from one alternator, or a single output battery charger, without connecting the batteries together. This means that current cannot flow between batteries, so discharging one cannot discharge the other, but they can still all receive a charge from a common charging source. These devices are sometimes referred to as charge splitters and are commonly used on larger boats that have multiple isolated battery banks (e.g. house/service, windlass, bow thruster etc.).

This Argofet has a maximum charge current rating of 200A (alternator output 200A max.) and can charge 2 isolated batteries simultaneously. It will work with 12V or 24V battery systems and auto-detects the system voltage when connected.

Virtually zero voltage drop

These Argofet splitters utilise Field-Effect Transistors (FET) and in contrast with charge splitters that use diodes, they incur virtually no voltage drop. For example, the voltage drop in the Argofets is less than 0.02V at low current and an average of 0.1V at higher currents. This maintains the voltage output of the alternator or battery charger and there is no need to increase the output voltage of the charging source to compensate for voltage drop (as long as care is taken to keep cable lengths short and of sufficient cross section to minimise voltage drop in the cable run). 

Alternator energise input

Some alternators need to detect a DC voltage on the B+ output terminal to start charging. Obviously, DC voltage will be present when the alternator is directly connected to a battery, however, fitting a battery isolator will prevent any return voltage/current from the batteries to the B+ terminal and the alternator won't start. These Argofet Isolators have a special current-limited energise input that will provide voltage to the B+ terminal when the ignition is activated or the engine run/stop switch closed, allowing the alternator to operate as normal.