Victron Energy Argofet Battery Isolators, Alternator Energize Input, 12/24V Auto Ranging

Overview

The Victron Energy Argofet is a FET-based battery isolator range for charging separate battery banks from one alternator or a single-output battery charger without linking those banks together. This helps keep a start battery from being pulled down by house or accessory loads, which matters on cruising boats, fishing boats, and other vessels with more than one DC battery bank.

The range covers 100 A and 200 A maximum charge current versions, with configurations for 2 or 3 batteries. All listed versions are auto-ranging for 12V and 24V systems, use M8 bolt connections, measure 65 x 120 x 200 mm, and weigh 1.4 kg.

The FET layout keeps voltage drop very low compared with diode-style isolators: less than 0.02 V at low current and about 0.1 V at higher current. The alternator energize input is useful where an alternator needs DC voltage at B+ before it begins charging.

Key features

• Charges 2 or 3 battery banks from one alternator or single-output battery charger while keeping the banks electrically separated.
• FET-based isolation keeps voltage drop below 0.02 V at low current and around 0.1 V at higher current.
• Auto-ranging 12V and 24V operation suits common marine DC charging systems.
• Alternator energize input can power B+ when the engine run/stop switch is closed, helping alternators that need voltage before charging starts.
• M8 bolt connections give a clear fit point for high-current battery and alternator cabling.
• Shared 65 x 120 x 200 mm size across the range makes panel and locker layout easier to plan.

Variants

This Argofet range is offered in multiple charging and battery-bank configurations. The differences are maximum charge current and the number of battery outputs.

The listed versions share 12V and 24V auto-ranging operation, M8 bolt connections, 65 x 120 x 200 mm dimensions, and 1.4 kg weight. Match the current rating to the alternator or charger output, then match the output count to the number of battery banks that need charging.

• ARG100201020: 100 A maximum charge current with outputs for 2 batteries. This suits a two-bank layout such as start and house batteries when the charging source is within the 100 A rating.
• ARG100301020: 100 A maximum charge current with outputs for 3 batteries. This keeps three separate banks on the same charging source while staying within a 100 A charge current limit.
• ARG200201020: 200 A maximum charge current with outputs for 2 batteries. This version fits two-bank systems using a higher-output alternator or charger within the 200 A rating.
• ARG200301020: 200 A maximum charge current with outputs for 3 batteries. This is the three-bank option for systems that need the 200 A charge current rating.

Installation and setup

Plan the installation around the charging source and the battery bank positives. The alternator or single-output charger connects to the input, and the battery bank positives connect to output 1, output 2, and output 3 on 3-bank versions. Keep charge cables short and sized for the current, because cable loss can still affect charging performance.

The energize blade terminal connects to the engine run/stop switch when that function is needed, and the ground blade terminal connects to the common negative bus bar. Both blade terminal connections call for a minimum cable cross section of 2.5 mm2. Mount the unit on a non-flammable surface and leave enough room around the M8 terminals for secure cable routing and later inspection.

Compatibility and fit

Use the 100 A versions with charging sources up to 100 A and the 200 A versions with charging sources up to 200 A. The 2-battery models suit simple start and house-bank layouts, while the 3-battery models suit boats with an additional separate bank that needs alternator or charger input without being tied directly to the others.

This is a good match for boats that need alternator charging across separate battery banks without using the isolator as a battery switch, charger, or monitor. It belongs in a properly planned DC charging system where cable size, overcurrent protection, mounting surface, and service access are checked before installation.