ORION XS 1400 dual batteries charging

Been mulling over something similar for my static caravan setup and figured I'd throw it out here.

Running a 24V alternator situation got me thinking about how the Orion XS 1400 handles dual battery banks — specifically when your starter and leisure banks are mismatched in capacity. Mine's 12V rather than 24V but the principle's the same.

The question I keep coming back to: does the XS 1400 actually manage charge distribution sensibly when your banks are wildly different sizes? Say your starter bank is relatively small lead acid and your service bank is a much chunkier setup — is the charger smart enough to prioritise correctly, or does it just blast away regardless?

From what I've read the Orion XS uses input voltage sensing to determine alternator load, which sounds good on paper. But I'm sceptical whether it truly "knows" how full each bank is without proper comms back to a BMS or at least a Victron BMV on each bank.

Few things I'd want to know from anyone who's actually run this config:

• Did you wire it input from starter, output to service or the other way?
• Any thermal issues running it hard off a mid-sized alternator?
• Anyone paired it with a Fogstar Drift lithium on the service side?

Feels like the marketing glosses over the nuance of genuinely mismatched banks. Real-world data always beats a spec sheet.

Anyone here actually running dual banks through one of these rather than splitting across two separate DC-DC units?

@RelayDream worth clarifying — the Orion XS 1400 is a single output DC-DC charger, so it charges one battery bank at a time. If you're running 24V input to a 12V leisure bank in your static van, that's straightforward enough.

For dual battery scenarios you'd either need two separate Orion XS units (one per bank) or look at sequencing them somehow. I run a similar arrangement in my tiny house setup — Victron handles priority sequencing via the BMS signals rather than the charger itself doing anything clever.

Also worth noting the 1400 has proper MPPT-style adaptive charging unlike older Orion models, so your 24V alternator input should be handled cleanly without dumping voltage spikes into a lithium bank.

What chemistry are your batteries? That'll change the conversation significantly around absorption settings.

@SaltyRanger is right, one output, that's it.

If you genuinely need to charge two separate banks you're looking at either two units or a different approach entirely. I ran a similar setup in my static for a bit — ended up just using a Victron Orion-Tr Smart per bank, cleaner solution tbh.

Worth asking yourself if you actually need dual banks or if you're overcomplicating it. A lot of people think they do and then realise one decent sized lithium does the job fine. What's the actual use case here — loads split across two banks or just redundancy?

Aye, @ZFS_OffGrid and @SaltyRanger have got it covered — one output, full stop.

Only way I ever managed to "charge two banks" with a single unit was by accidentally wiring them together and calling it a feature. Wasn't intentional, wasn't clever, and the magic smoke that followed was neither.

Got a static van setup myself and went down this rabbit hole last year.

Ended up running two separate Orion XS units — one per bank. Pricier upfront but the Victron app gives you proper visibility on each one independently, which I found worth it for peace of mind.

If budget's tight, @ZFS_OffGrid's point about a combiner/splitter route is worth exploring, though you'll lose some of the smart charging benefits depending on what you pair it with.

What are your two banks actually for? If it's just leisure + engine start, a BMS with a load-sharing setup might sidestep the whole problem entirely depending on your draw requirements.