Victron Argo FET Battery Isolator 100/200 Amp, 2/3 Batteries

The Victron Argofet Battery Isolator is a FET-based battery isolator that allows one alternator or single-output battery charger to simultaneously charge two or three independent battery banks — without connecting the batteries together. Available in 100A and 200A versions with either 2 or 3 battery outputs, the Argofet range offers the same fundamental battery isolation function as conventional diode isolators, but with virtually no voltage drop — eliminating the need to increase the alternator output voltage to compensate for isolator losses.

Unlike diode battery isolators, which typically cause a voltage drop of 0.5–0.7V across the Schottky diodes, the Argofet uses field-effect transistors (FETs) to perform isolation. The voltage drop is less than 0.02V at low current and averages just 0.1V at higher currents — meaning that batteries receive virtually the full alternator output voltage, enabling faster and more complete charging without any charger or alternator voltage adjustment. This is the primary and most important advantage of FET isolation over diode isolation in practical marine, RV, and vehicle installations.

The Argofet also incorporates a dedicated alternator energize input that solves a common problem with battery isolators: some alternators require DC voltage on the B+ terminal to begin charging. When a battery isolator is inserted between the alternator and the batteries, the return path is blocked and the alternator may fail to start charging. The Argofet's current-limited energize input supplies the necessary B+ voltage when the engine run/stop switch is closed — enabling the alternator to start charging reliably without any modification to the alternator or its wiring.

All four Argofet models — 100-2, 100-3, 200-2, and 200-3 — share the same physical enclosure, M8 bolt connections, and aluminium heatsink construction. A blue LED illuminates when voltage is present on the input. The Argofet automatically adjusts to 12V and 24V systems without any configuration.

Features

Virtually No Voltage Drop — FET Technology

FET transistors replace conventional Schottky diodes, reducing voltage drop from a typical 0.5–0.7V (diode) to less than 0.02V at low current and an average of just 0.1V at higher currents — allowing batteries to be charged at virtually the full alternator output voltage for faster, more complete charging without any voltage adjustment.

Simultaneous Multi-Battery Charging from One Source

Allows one alternator or single-output charger to charge two or three separate battery banks simultaneously — keeping each bank electrically isolated from the others so that discharging one bank (such as an accessory or bow thruster battery) cannot discharge the starter battery or other banks.

Alternator Energize Input — Prevents Alternator Start Failure

A current-limited energize input supplies the DC voltage required by some alternators on the B+ terminal to begin charging — automatically powered when the engine run/stop switch is closed. This eliminates the common problem of alternators failing to start charging when isolated from the battery by a diode or FET splitter.

Available in 100A and 200A — 2 or 3 Battery Outputs

Available in four configurations: Argofet 100-2 (100A, 2 batteries), Argofet 100-3 (100A, 3 batteries), Argofet 200-2 (200A, 2 batteries), and Argofet 200-3 (200A, 3 batteries) — covering installations from small two-battery marine systems up to large three-bank commercial or recreational vehicle installations at 200A alternator capacity.

Automatic 12V / 24V System Detection

The Argofet automatically adjusts to 12V or 24V system voltage — no configuration, jumpers, or voltage selection required. Both system voltages are supported across all four current and output configurations.

M8 Bolt Connections — Suitable for High-Current Cabling

All input and output connections use M8 bolts, accepting cable lugs appropriate for the high-current cabling required at 100A and 200A — ensuring low-resistance, secure connections that will not loosen under vibration in marine and vehicle applications.

Blue LED Status Indicator

A blue LED illuminates when voltage is present on the Argofet input, providing an immediate visual confirmation that the isolator is energised and the alternator or charger input is live — without requiring any measurement or additional monitoring equipment.

Direct Replacement for Diode Battery Isolators

The Argofet is a direct replacement for conventional diode battery isolators, using the same wiring topology with one input from the alternator and separate outputs to each battery bank — requiring no changes to system architecture, only the removal of the existing diode isolator and fitting of the Argofet in its place.

Specifications

Datasheets and Manuals

Datasheet

Product Manual