Victron's Orion-Tr Smart has been the go-to DC-DC charger for UK campervan and motorhome builds for years. But in 2024, Victron released the Orion XS — a completely redesigned charger that's smaller, more efficient, and packed with features the Orion-Tr Smart lacks. This guide compares both products head-to-head so you can decide which one to buy for your installation.
What Do These Chargers Do?
Both the Orion-Tr Smart and Orion XS are DC-DC battery-to-battery chargers. They charge your leisure battery (lithium, AGM, or gel) from your vehicle's alternator via the starter battery. This is the modern replacement for split-charge relays, and it's essential for vehicles with smart alternators — which includes almost every UK vehicle built after 2015.
Smart alternators vary their output voltage to save fuel, dropping as low as 12.4V when the engine is warm. A simple relay or voltage-sensing relay won't charge a leisure battery properly under these conditions. A DC-DC charger boosts the voltage to the correct charging profile for your leisure battery chemistry, regardless of what the alternator is doing.
Head-to-Head Specification Comparison
Here's the full comparison between the most popular models in each range — the Orion-Tr Smart 12/12-30 and the Orion XS 12/12-50:
| Specification | Orion-Tr Smart 12/12-30 | Orion XS 12/12-50 |
|---|---|---|
| Max charge current | 30A | 50A (configurable 0–50A) |
| Nominal input voltage | 12V (8–17V range) | 12V (8–17V range) |
| Nominal output voltage | 12V | 12V |
| Peak efficiency | ~87% | ~98% |
| Dimensions (mm) | 186 × 110 × 67 | 191 × 67 × 38 |
| Weight | 1.1 kg | 0.5 kg |
| IP rating | IP43 (indoor use) | IP65 (fully weatherproof) |
| Bluetooth | Yes (built-in) | Yes (built-in) |
| VE.Direct port | No | Yes |
| GX device integration | Via Bluetooth only | Native via VE.Direct |
| VE.Smart Networking | Yes | Yes |
| Engine detection | Voltage sense or remote on/off | Voltage sense (configurable thresholds), remote on/off, or alternator input |
| Configurable current limit | Fixed (30A max output) | Yes (0–50A, adjustable in app) |
| Battery presets | LiFePO4, AGM, Gel, custom | LiFePO4, AGM, Gel, custom |
| Multi-phase charging | Bulk, absorption, float | Bulk, absorption, float, storage |
| Parallel operation | Yes (2 units, 60A total) | Yes (multiple units) |
| Wiring connector | Screw terminals | Push-in spring terminals |
| Typical UK price | £160–£200 | £220–£270 |
Efficiency: The Biggest Upgrade
The efficiency difference is dramatic. The Orion-Tr Smart operates at roughly 87% efficiency, which means 13% of the power drawn from the starter battery is lost as heat. At 30A output on a 12V system, that's about 50W of heat dissipation. This is why the Orion-Tr Smart gets hot during operation and needs good airflow.
The Orion XS achieves up to 98% efficiency. At 50A output, it wastes only about 12W as heat — despite delivering nearly twice the power. This means:
- Less heat — the XS barely gets warm, even at full output.
- More flexible mounting — no need for ventilation space around the unit.
- Less strain on the alternator — drawing 50A from the starter battery delivers 49A to the leisure battery, not 43.5A as it would at 87% efficiency.
- Smaller size — less heat means no need for a bulky heatsink, which is why the XS is 50% smaller and half the weight.
Size and Mounting
The Orion XS is remarkably compact. At just 38mm thick, it's essentially a flat slab that can be mounted in tight spaces where the Orion-Tr Smart simply wouldn't fit. The IP65 rating means you can mount it in the engine bay, under the vehicle, or anywhere exposed to moisture and dust — a significant advantage over the IP43 Orion-Tr Smart, which must be mounted in a dry, ventilated location.
For UK campervan builds where space under the passenger seat or in a garage area is at a premium, the XS's form factor is a genuine improvement.
GX Device Integration
The Orion-Tr Smart connects to a Cerbo GX via Bluetooth only. This works but has limitations — Bluetooth range is short, data updates are slower, and the connection can be unreliable through metal enclosures.
The Orion XS has a VE.Direct port, providing a wired connection to the Cerbo GX. This gives you:
- Reliable, always-on communication.
- Full data logging on the VRM portal.
- DVCC integration — the GX device can coordinate the Orion XS with your MPPT solar chargers and BMS.
- Firmware updates via the GX device.
If you're building a Victron system with a GX device, the XS integrates far more cleanly than the Orion-Tr Smart.
Configurable Current Limit
The Orion-Tr Smart 12/12-30 always tries to deliver its full 30A output when the battery needs it. You cannot reduce this in software.
The Orion XS allows you to set a custom current limit from 0 to 50A via the VictronConnect app. This is useful for:
- Protecting smaller alternators. If your vehicle has a 70A alternator, you probably don't want a DC-DC charger pulling 50A of it. Set the limit to 25–30A.
- Matching to cable capacity. If your existing wiring only supports 30A, set the limit to 30A and avoid re-cabling.
- Gradual ramp-up. The XS supports configurable ramp-up time to avoid shocking the alternator with a sudden current draw.
Engine Running Detection
Both chargers need to know when the engine is running so they only charge from the alternator, not drain the starter battery while parked.
The Orion-Tr Smart offers two methods:
- Voltage sense: Starts charging when starter battery voltage exceeds a threshold (default 13.1V). Works for most vehicles.
- Remote on/off wire: Connect to an ignition-switched 12V source for definitive engine detection.
The Orion XS adds more flexibility:
- Voltage sense with configurable thresholds: You can set custom start and stop voltages in the app, fine-tuning for smart alternator behaviour.
- Remote on/off wire: Same as the Orion-Tr Smart.
- Alternator input: Dedicated input for direct alternator connection sensing.
When the Orion-Tr Smart Still Makes Sense
Despite the XS being the superior product on paper, there are situations where the Orion-Tr Smart remains a sensible choice:
- Budget. The Orion-Tr Smart 12/12-30 is around £160–£200, while the Orion XS 12/12-50 is £220–£270. If you're on a tight build budget and 30A is enough, the saving is meaningful.
- 30A is sufficient. For a 100–200Ah lithium battery that's also charged by solar, 30A from the alternator is often perfectly adequate. You don't need 50A unless you're charging a large bank primarily from driving.
- Proven reliability. The Orion-Tr Smart has been installed in thousands of UK campervans over several years. It's a known quantity with well-documented installation procedures and troubleshooting resources.
- Drop-in replacement. If you're replacing a failed Orion-Tr Smart, using the same model means no re-wiring and identical mounting holes.
When to Choose the Orion XS
- New builds. If you're starting from scratch, there's little reason not to go with the XS. The price premium is modest for a significantly better product.
- Large lithium banks (200Ah+). A 300Ah lithium bank can accept 150A+ of charge. At 30A from the alternator, it takes 10 hours of driving to fully charge from flat. At 50A, that drops to 6 hours.
- Space-constrained installations. The XS is half the size and weight, and can be mounted in the engine bay thanks to IP65.
- GX-integrated systems. If you're running a Cerbo GX, the VE.Direct connection on the XS provides proper wired integration.
- Hot climates or poor ventilation. The 98% efficiency means minimal heat, so ventilation requirements are essentially eliminated.
Can You Parallel Two Orion-Tr Smart Instead of One Orion XS?
Yes — two Orion-Tr Smart 12/12-30 units in parallel deliver 60A total, exceeding the XS's 50A. But two units cost £320–£400 vs £220–£270 for a single XS, take up twice the space, generate much more heat (100W combined vs 12W), and require more complex wiring. For more on this, see our guide on wiring two Orion-Tr Smart chargers in parallel.
The only scenario where parallel Orion-Tr Smart units make sense over an XS is if you specifically need 60A and already own one Orion-Tr Smart — buying a second is cheaper than replacing both with XS units.
Which Model Variants Are Available?
| Product | Input → Output | Max Current |
|---|---|---|
| Orion-Tr Smart 12/12-18 | 12V → 12V | 18A |
| Orion-Tr Smart 12/12-30 | 12V → 12V | 30A |
| Orion-Tr Smart 12/24-15 | 12V → 24V | 15A |
| Orion-Tr Smart 24/12-20 | 24V → 12V | 20A |
| Orion-Tr Smart 24/12-30 | 24V → 12V | 30A |
| Orion-Tr Smart 24/24-17 | 24V → 24V | 17A |
| Orion XS 12/12-50 | 12V → 12V | 50A |
As of early 2025, the Orion XS is only available in the 12/12-50 configuration. Victron is expected to expand the range with 24V variants and potentially different current ratings, but for now the XS is a 12V-to-12V product only.
Our Recommendation
For new UK campervan and motorhome builds, the Orion XS 12/12-50 is the better buy. It's smaller, runs cooler, integrates properly with a GX device, and the configurable current limit means you can dial it back to 30A if that's all your alternator or wiring can handle. The price premium over the Orion-Tr Smart 12/12-30 is typically £40–£70 — excellent value for a product that's better in almost every measurable way.
If you need a 24V input or output, the Orion-Tr Smart is currently your only option. And if you're on a strict budget with a modest battery bank (100Ah or less), the Orion-Tr Smart 12/12-30 remains a proven, reliable workhorse that will serve you well.
For installation details, see our step-by-step guide on installing a Victron Orion-Tr Smart DC-DC charger.
