Installatie Orion XS1400 in boot

Bit of an odd one here — I've been looking at the Victron Orion XS range for stepping up voltage between battery banks and wondering if anyone's actually run a similar 12V-to-24V setup in a practical install?

My situation is slightly different to the usual van stuff — I've got a 12V AGM bank (two Fogstar-sourced 100Ah units in parallel) in the van itself, and I'm toying with the idea of feeding a separate 24V lithium bank in my garden office via a DC-DC charger rather than running a whole new solar setup out there.

A few questions I can't quite nail down:

• Does the Orion XS handle the transition cleanly when the 12V source bank drops under load? Worried about it cutting in and out
• What profile settings are people using for the output side when charging into series-connected AGM batteries specifically? I know lithium is the trendy choice but the AGMs are what I've got
• Is there a meaningful efficiency difference between the 12/24-12A and the beefier models for this kind of inter-bank charging scenario?

I realise running AGM in series introduces balancing concerns too — is anyone actively monitoring cell-level balance across a series pair, or just hoping for the best?

Would be curious whether anyone's done a permanent install like this rather than just using it as a travel charger. The Victron app integration looks promising for keeping an eye on things remotely, which matters when the office is at the bottom of the garden.

@StuKnight — ran a 12V-to-24V step-up config in my Transit conversion last winter, though not with the XS specifically. Few things worth flagging for a UK install:

• The Orion XS 50A needs decent cable sizing — I used 35mm² on mine and it still ran warm during sustained loads
• Make sure your alternator protection is sorted; the smart algorithm on Victron's DC-DC units genuinely does save your vehicle alternator from cooking itself
• If you're on a split-charge relay setup rather than a proper B2B, swap it out first — the XS deserves a cleaner input

What's your source bank chemistry? I ask because LiFePO4 on the input side behaves very differently to AGM when the XS is pulling hard. That changes your configuration quite a bit.

@StuKnight — worth noting the XS range is specifically a battery-to-battery charger, so it's doing proper multi-stage charging rather than just voltage conversion. That distinction matters quite a bit for your 24V bank's longevity.

I've run a similar topology in my motorhome — 12V lithium service bank feeding a 24V bow thruster bank via a DC-DC charger. Key things I'd check:

• Input current draw on your 12V side will be roughly double your output current (plus losses), so cable sizing is critical
• The XS handles up to 50A output, but confirm your 12V bank can sustain that continuous load
• Victron's VictronConnect app gives you real-time monitoring which is genuinely useful for diagnosing any gremlins

The Orion XS is well-supported in the UK — Bimble Solar and EMAUK both stock them with decent technical backup if you need pre-sales advice.