Victron Energy Argofet 200-2AC Battery Isolator for 2 Batteries, 200A — Low Voltage Drop, Auto 12/24V

The Victron Energy Argofet 200-2AC is a two-battery FET isolator that lets one alternator charge two separate batteries safely and efficiently without tying them together.

The Argofet 200-2AC replaces traditional diode isolators by using MOSFET (FET) technology to achieve extremely low voltage drop and automatic 12/24V compatibility. Designed for boats, RVs and commercial vehicles, it keeps the starter battery protected while allowing an accessory or house battery to receive charge simultaneously. Its low voltage loss preserves alternator output and helps batteries reach their full charge more quickly compared with diode-based units.

How does the Argofet 200-2AC prevent the starter battery from discharging?

The isolator electrically separates the starter and accessory batteries so loads on one battery won’t pull current from the other. It uses FET switches that conduct when the alternator puts out charging voltage, but block current flow between batteries when the alternator is off.

• Independent battery paths prevent accessory drains from affecting starter power.
• Automatic switching engages only during alternator charging.
• Solid-state FETs provide fast, reliable isolation without mechanical relays.

Will this work in my 12V or 24V electrical system?

The Argofet 200-2AC is auto-ranging and will operate correctly on both 12-Volt and 24-Volt systems without manual changes. This makes it suitable for mixed-fleet installations and simplifies inventory for workshops or installers who service different vehicles.

• Automatic detection of 12V or 24V systems—no jumper settings required.
• Sized for systems where a single alternator must charge two batteries up to 200A shared load.
• Compatible with standard automotive and marine charging setups when correctly wired and fused.

How efficient is the Argofet compared with diode isolators?

Unlike diode isolators that have significant forward voltage drop, the Argofet FET design delivers near-zero voltage loss. This higher efficiency leads to more effective charging, especially important for higher-current alternators and modern lead-acid or lithium battery systems.

• Voltage drop typically less than 0.02 V at low currents and about 0.1 V at higher currents.
• Less wasted alternator output means faster, fuller battery charging.
• Reduces the need to increase alternator voltage to compensate for losses.

What installation and wiring considerations should I be aware of?

Proper cable sizing and short run lengths ensure the isolator performs as intended and minimizes heat and voltage drop on the conductors. The Argofet itself introduces minimal loss, but attention to cables, fusing and secure connections is key to safe, reliable operation.

• Use appropriately sized battery cable and keep runs short where possible.
• Install fuses or circuit breakers on each battery feed per local electrical codes and alternator specs.
• Mount in a ventilated, dry location with easy access for inspection and maintenance.

Who is this for? The Victron Energy Argofet 200-2AC is ideal for boat owners, RV enthusiasts, commercial vehicle operators and professional installers who need a compact, reliable way to charge two batteries from one alternator without linking them together. It suits systems that demand high charging efficiency, automatic 12/24V compatibility and protection of the starter battery from accessory loads. If you want near-zero voltage loss, solid-state reliability, and a straightforward installation for dual-battery charging, this unit is a practical choice.