Victron Energy Argofet 100-2 Two batteries 100A Battery Isolator

Technical Specifications  User manual 

Victron Argofet Battery Isolators – Efficient Multi-Battery Charging Without Voltage Loss

The Victron Argofet Battery Isolator enables simultaneous charging of two or more batteries from a single alternator or battery charger—without connecting the batteries directly. This ensures that discharging one battery (e.g., for accessories) won’t drain the starter battery.

Key Advantages

✔ Charge Multiple Batteries Safely

• Supports charging of multiple batteries from one alternator or charger
• Keeps batteries electrically isolated, preventing cross-discharge
• Ideal for systems with starter and accessory batteries

✔ Virtually Zero Voltage Loss

• Unlike traditional diode-based isolators, Argofet units use FET technology
• Voltage drop is minimal:
  • < 0.02V at low current
  • ~0.1V average at higher loads
• No need to compensate by increasing alternator output voltage

✔ Optimized System Efficiency

• Maintains efficient charging without the need for additional voltage adjustments
• Keeps your battery system balanced and protected

Installation Considerations

✔ Keep Cable Lengths Short & Properly Sized

• Voltage drop can still occur through long or undersized cables
• Example:
  • 100A through 10 m of 50 mm² cable (AWG 0) = 0.26V drop
  • 50A through 5 m of 10 mm² cable (AWG 7) = 0.35V drop
• Use short, thick cables to minimize loss

Built-In Alternator Energize Input

Some alternators require DC voltage on the B+ terminal to begin charging. Unlike a direct battery connection, isolators block return current—so alternators may not activate. The new Argofet models solve this with a current-limited energize input, providing the required voltage to B+ when the engine’s run/stop switch is closed.

Ideal For:

• Marine systems
• RVs and camper vans
• Off-grid battery banks
• Automotive dual-battery setups