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Victron Energy Orion DC-DC Converter
The ultimate guide and sizing calculator for Victron Orion-Tr Smart isolated and non-isolated DC-DC converters. Perfect for camper vans, marine, and off-grid systems.
Orion DC-DC Sizing Calculator
Find the exact Victron Orion-Tr Smart model you need, plus the correct fuse and cable size for your dual battery setup.
Recommended Model
Required Fuse Size
Minimum Cable Size
Understanding the Victron Orion Range
What is a DC-DC Converter?
A DC-DC converter (often called a Battery-to-Battery charger) takes power from your vehicle's alternator (starter battery) and safely charges your auxiliary/house battery bank while driving. Unlike a simple voltage-sensitive relay (VSR), the Victron Orion provides multi-stage charging (Bulk, Absorption, Float) specifically tuned for Lithium (LiFePO4), AGM, or Gel batteries.
Isolated vs. Non-Isolated: Which do you need?
- Isolated (Galvanically Isolated): Creates a complete electrical separation between the input and output. Required if your vehicle has a smart alternator, if you are connecting batteries of different chemistries, or for marine applications to prevent galvanic corrosion. It also protects sensitive electronics from voltage spikes.
- Non-Isolated: Shares a common ground between input and output. It is cheaper, slightly more efficient, and smaller, but should only be used when the starter and house batteries are the same chemistry and the vehicle has a standard alternator.
The "Smart" Advantage (Bluetooth)
The modern Orion-Tr Smart range features built-in Bluetooth. Using the free VictronConnect app (available on iOS and Android), you can monitor voltage, current, and temperature, and customize the charging algorithm to perfectly match your specific battery brand (Victron, Battle Born, Renogy, etc.).
Choosing the Right Amp Rating
The amp rating you choose depends on your alternator size and your house battery capacity. A general rule of thumb is that the DC-DC converter should not exceed 20-30% of your alternator's rated output to prevent overloading the vehicle's electrical system.
| House Battery Bank | Recommended Orion Size | Charge Time (0-80%) |
|---|---|---|
| 100Ah Lithium | 18A to 20A | ~4 to 5 hours |
| 200Ah Lithium | 30A to 40A | ~4 to 6 hours |
| 300Ah+ Lithium | 40A to 50A (or multiple units) | ~6 to 8 hours |
IP67 Waterproof
Fully potting and sealed. Can be mounted in the engine bay, under a van, or in a marine bilge without worry.
Bluetooth Smart
Monitor and configure via the VictronConnect app. Update firmware and tweak absorption/float voltages instantly.
Engine Shutdown Detection
Automatically detects when the engine turns off and safely enters storage mode to prevent draining the starter battery.
Frequently Asked Questions
Do I need an Orion if I have a Victron SmartSolar MPPT?
Yes, they serve different purposes. The SmartSolar charges your house batteries from solar panels. The Orion charges your house batteries from your vehicle's alternator while driving. For a complete off-grid system, you typically need both.
Can I use an Orion to charge a Lithium battery from a Lead-Acid starter battery?
Absolutely. This is one of the most common use cases. The Orion's adjustable output voltage allows you to set the exact absorption and float voltages required by your Lithium house bank, regardless of what the alternator is producing.
Why is my Orion getting hot?
DC-DC converters are not 100% efficient; they typically operate at 90-95% efficiency. The remaining 5-10% is lost as heat. It is normal for the casing to reach 60°C (140°F) under full load. Ensure it is mounted vertically on a metal surface for passive heat dissipation.
Is Victron Orion compatible with smart alternators?
Yes, but you MUST use an Isolated model. Smart alternators (Euro 6 vehicles, modern trucks) vary their voltage wildly. The Isolated Orion handles this input variance safely and outputs a stable charging voltage to your house batteries.
Power Your Off-Grid Adventures
Size your Victron Orion correctly and keep your house batteries fully charged on the road.
Open Sizing Calculator