Victron Energy Argodiode Battery Isolators, Schottky Diodes

Overview

The Victron Energy Argodiode is a diode battery isolator range for charging two or three battery banks from one alternator without tying those banks together electrically. On a boat, that means a service or accessory battery can be discharged without also pulling down the starter battery.

The range covers 12V and 24V nominal battery systems, with model ratings from 80A to 180A. It uses Schottky diodes to keep voltage drop low, at approximately 0.3 V at low current and approximately 0.45 V at rated output, which is important when alternator charging voltage has to reach batteries through long marine cable runs.

These isolators suit engine-driven charging layouts on cruising boats, fishing boats, workboats, and other vessels that need a simple way to split alternator output between separate battery banks. The correct model depends on alternator output, the number of battery banks, and whether the installation needs an alternator energize input.

Key features

• Allows one alternator to charge two or three battery banks while keeping those banks separated from each other.
• Supports 12V and 24V nominal battery systems across the range.
• Schottky diode layout keeps voltage drop to approximately 0.3 V at low current and approximately 0.45 V at rated output.
• Available ratings cover 80A, 100A, 120A, 140A, 160A, and 180A alternator and charge current requirements.
• Compensation diode can be used to help offset voltage loss across the isolator when connected into a suitable alternator sensing setup.
• AC models include a current-limited alternator energize input for alternators that need voltage on B+ before they begin charging.
• Uses stud connections for main charging cables, with M6 studs on lower-current models and M8 studs on higher-current models.
• 6.3 mm Faston terminal connection is used for compensation and energize wiring where applicable.

Variants

This Argodiode range is offered in several configurations that vary by maximum charge current, number of battery outputs, main cable stud size, physical size, and alternator energize input. The models cover 80A to 180A systems and either two or three battery banks, so the selection should match the alternator output and the number of banks being charged.

The 80-2SC version is the only listed model without an alternator energize input. The AC versions include that energize function. Across the listed models, 12V and 24V nominal battery system support, Schottky diode isolation, and the compensation diode function remain consistent.

Installation and setup

Mount the isolator in a dry protected electrical space such as an engine room electrical panel area or battery compartment, not on an exposed deck. The housing can become hot in service, so it should be fixed to a non-flammable surface with enough space around it for heat to dissipate and for cable terminals to remain accessible.

Before wiring, disconnect the battery negative cables. The alternator positive output connects to the isolator input, and the positive leads for each battery bank connect to the numbered outputs. The battery negatives should return to a common negative bus. Cable length and cable cross-section matter in this type of installation because cable voltage drop adds to diode voltage drop.

Compatibility and fit

The current rating of the isolator should be equal to or greater than the alternator output. Two-bank models suit layouts with a starter bank and one service or house bank. Three-bank models suit vessels with an additional battery bank, such as a bow thruster, windlass, electronics, or auxiliary bank, when the charging layout calls for those banks to remain separated.

For installations with alternators that do not start charging unless they see voltage at B+, use one of the AC models with the energize input. The energize terminal is normally tied into the engine run or stop switch circuit, while the compensation terminal can be used with a compatible alternator voltage sense connection to help correct for isolator voltage drop.

Use cases on board

This product range is a practical match for boats that use one alternator to maintain separate battery banks and where simple diode isolation is preferred over combining relays or more complex charge management. It is especially useful where the starter battery must stay protected while house loads, electronics, pumps, lighting, or deck equipment draw from a separate bank.