Overview

Argo Diode Battery Isolator (120-2AC) – Charge Multiple Batteries Without Draining Your Starter

The Argo Battery Isolator allows you to safely charge multiple batteries from a single alternator while keeping them electrically isolated from each other.

This means your starter battery stays protected. Running accessories from a secondary battery will not drain your ability to start your engine.

This is especially important in RV, marine, and off-grid systems where multiple battery banks are used for different purposes.

The 120-2AC model also solves a common issue with modern alternators. Some alternators require voltage on the output terminal (B+) to begin charging. Traditional isolators can block this, preventing the alternator from starting.

The AC series includes a built-in energize input to ensure proper alternator startup, making it a reliable solution for a wider range of systems.

Features

Dual Battery Isolation
Allows two batteries to be charged from a single alternator while preventing discharge between them.

Protects Starter Battery
Ensures that accessory loads cannot drain the starting battery, improving system reliability.

Low Voltage Drop (Schottky Diodes)
Uses high-efficiency Schottky diodes to minimize voltage loss:

• Approximately 0.3V at low current
• Approximately 0.45V at rated output

Voltage Compensation Diode
Includes a compensation diode to slightly increase alternator output voltage, offsetting voltage drop across the isolator.

Alternator Energize Input (AC Model Advantage)
Built-in current-limited energize input ensures the alternator begins charging properly, even in systems where isolators would otherwise block startup voltage.

Improved Charging Performance
Helps maintain proper charging behavior when installed correctly, avoiding undercharging and premature battery aging.

Specifications

Model:
120-2AC (two battery outputs)

Function:
Allows one alternator to charge two batteries while keeping them electrically isolated

Diode Type:
Schottky diodes for low voltage drop

Voltage Drop:
Approximately 0.3V at low current
Approximately 0.45V at rated current

Outputs:
2 battery outputs

Alternator Compatibility:
Compatible with alternators requiring B+ energizing via integrated energize input

Energize Input:
Current-limited input activated when engine run/stop switch is engaged

Voltage Compensation:
Integrated compensation diode to offset voltage drop

Installation Note:
Installing an isolator between the alternator and batteries reduces charge voltage. Proper configuration or compensation is required to ensure batteries reach full charge and avoid premature aging.

Applications:
RV electrical systems
Marine systems
Dual battery setups
Off-grid and mobile power systems