On every tow-vehicle board, the dual-battery thread ends up in the same place. Someone recommends a REDARC BCDC, because it is what the dealer fits and what the accessory catalogue lists. Someone else recommends a Victron Orion. The argument that follows is usually about brand loyalty rather than about what the two actually do differently.
They do differ, in ways that decide the choice for most people. Here is the comparison on the points that matter, with the objection owners raise about each stated plainly.
Start with the objection about REDARC, because it is half wrong
The claim that circulates is that the BCDC1225 does not support lithium.
That is true of the original BCDC1225 and not true of the current BCDC1225D. The D model added a dedicated LiFePO4 charging profile alongside the AGM, gel, lead-acid and calcium profiles, and it is the D that has been sold for years. An owner with an old non-D unit and a new lithium bank has a genuine mismatch. An owner buying today does not.
So if lithium support is the reason you were told to avoid REDARC, it is not a good reason. The real differences are elsewhere.
The comparison
| Victron Orion XS 12/12-50 | REDARC BCDC1225D | |
|---|---|---|
| Charge current | 50 A | 25 A |
| Lithium profile | Yes | Yes, on the D model |
| Solar input | No; a separate MPPT does that | Yes, built-in MPPT, solar prioritised |
| Engine detection | Voltage sensing with a smart-alternator mode, plus optional ignition wire | Ignition wire, or voltage sensing on some models |
| Configuration | Bluetooth app | Fixed profiles; no app on the classic model |
| Maximum efficiency | 98.5% | Not published in the same terms |
| Suited bank size | Larger banks, given the current | 75 to 200 Ah, per REDARC's guidance |
Two things on that table decide most purchases.
The solar input, which is REDARC's genuine advantage
The BCDC1225D has a solar input with its own MPPT regulator, and it prioritises solar over the alternator when both are available. For a tow vehicle with a small panel on the roof or a portable panel at camp, that is one box doing two jobs, and it is the strongest argument for it. Owners who value simplicity choose it for this and they are right to.
The Orion XS has no solar input. Solar on a Victron system means a separate MPPT controller, which is an extra device and an extra cost. What you get in return is a controller sized to the array rather than to whatever the DC-DC charger's input can handle, and one that shares its data with everything else.
If the tow vehicle carries solar and you want one box, that favours REDARC. If the solar lives on the trailer, which it usually does, the argument disappears.
Current, which is Victron's
Fifty amps against twenty-five. On a lithium bank that will accept everything offered, double the current is roughly half the driving time to recharge.
That matters less than it sounds if the alternator cannot supply it. A 50 amp charger on a small alternator in a vehicle running air conditioning in traffic is asking the alternator to work hard, and a rule of thumb on the boards, that the charger should take no more than about a third of the alternator's rating, is worth respecting. Size to the alternator first. But on a vehicle with a modern high-output alternator, the extra current is real and it is the reason the XS is the unit owners on the Ranger and Gladiator boards are fitting for trailer batteries.
Engine detection, which decides whether it works on a modern vehicle
A smart alternator varies its voltage and shuts down when the vehicle decides no charge is needed. A DC-DC charger that watches only for a voltage threshold either fails to start on a smart alternator or, worse, drains the starter battery when the engine is off.
Both units can be wired to an ignition feed, which sidesteps the problem. The difference is what happens without one. The Orion XS has a smart-alternator mode with lower thresholds, a delayed start to let the starter battery recover, and a behaviour that backs its own current off rather than dropping out when input voltage sags. Our Orion XS versus Orion-Tr Smart guide lists the actual thresholds.
If your vehicle has a smart alternator and running an ignition wire is awkward, this is the deciding difference.
The app, and the ecosystem question
The Orion XS is configured and monitored in VictronConnect over Bluetooth, and it shares data with a SmartShunt and an MPPT in the same app. You can see what the alternator is delivering, change the current limit from the driver's seat, and adjust the lithium voltages to what your battery specifies.
The classic BCDC is set by fixed profiles with no app. REDARC's newer units add connectivity, but the BCDC1225D that the boards are arguing about is the simple one.
Whether that matters depends on whether you want to adjust anything. Plenty of owners want a box that works and never want to see a setting. Others want to know what is happening. Neither is wrong, but know which you are before you buy, because it is a permanent difference.
The Ecoflow question
A third option comes up on the same threads: skip the dual battery entirely and carry a portable power station. It is a fair answer for a weekend and a phone charger. It is not an answer for a trailer with a fridge, a pump and lights that need charging while you drive, because the power station does not charge the trailer's own battery and has to be carried in and out. The dual-battery-or-power-station choice is about how you camp, and it is worth settling before choosing a charger.
What to buy
- Trailer battery charged from the tow vehicle, shared chassis ground: Orion XS.
- Separate grounds, or a marine install: Orion-Tr Smart isolated.
- Modest bank, shared ground, 30 amps enough: Orion-Tr Smart non-isolated.
- One box with solar on the vehicle, no app wanted: that is the REDARC case, and we do not stock it, so we will say so rather than talk you out of it.
Send us the vehicle, its alternator rating, the battery bank and where the solar lives, and we will tell you which of these fits, including when it is not ours. Everything we stock ships from Upland, California.