Anyone know if a Victron SmartSolar 100/30 will work with a 24v battery bank?

Been trying to figure this out before I pull the trigger on buying one — can anyone confirm whether the SmartSolar 100/30 is compatible with a 24v battery bank?

My setup is on my narrowboat and I'm currently running a 12v system, but I'm seriously considering upgrading to 24v to reduce cable losses over the longer runs I've got. I've got two 100W panels on the roof at the moment and planning to add two more shortly.

From what I've read on the Victron site, it looks like the 100/30 auto-detects battery voltage (12v or 24v), but I wanted to check with people who've actually used it rather than just relying on the spec sheet. Has anyone made the switch from 12v to 24v mid-system and used this controller through the process?

Also — slightly related — if I do go 24v, would I need to reconfigure anything in the VictronConnect app or does it genuinely just detect it automatically when you first connect it to the bank? I've seen a few posts suggesting you have to set it manually on some firmware versions?

I've been looking at pairing it with a couple of Fogstar Drift 100Ah 24v LiFePO4 batteries if that makes any difference to the answer. Budget is fairly tight so I'd rather not have to replace the MPPT controller if I can avoid it — already spent a fortune on the boat refit! 😅

Any first-hand experience would be brilliant.

@LindaClark90 yeah it handles 12/24/48v, auto-detects on first boot. Got one on my static and it just sorted itself out when I hooked it up to my 24v Fogstar bank — didn't have to do anything clever.

One thing though — double check your panel voltage. The 100/30 has a 100v max input, so if you're stringing panels in series on a narrowboat make sure you're not pushing past that, especially on a cold morning when Voc spikes. Caught me out once.

The 30A is the output limit too, so on 24v that's roughly 720W max useful charge — worth knowing before you overspec your panels.

Victron's own spec sheet is dead clear on all this if you want to double check, just search "SmartSolar 100/30 datasheet."

Just to add to what @ZFS_OffGrid said — worth double-checking your panel array voltage doesn't exceed the 100V input limit on that controller. Easy mistake to make if you're stringing panels in series on a 24V bank.

I made that error planning my cabin setup — had panels that would've pushed 102V on a cold morning (Voc rises in low temps), which could fry the MPPT. Victron's MPPT calculator tool on their site is really useful for working out worst-case Voc before you commit.

Also, 30A output means you're capped at roughly 720W on a 24V bank, so factor that in if you're planning to expand your array later.

Running one on my static caravan with a 24v Fogstar bank and it's been rock solid — just make sure you let it do its auto-detection thing on first boot before you start fiddling with the VictronConnect app, otherwise you'll confuse the poor thing (and yourself).

Does anyone know whether the auto-detection causes issues if you've got a small residual charge already in the bank when you first connect it? Asking because on my tiny house build I've read conflicting things about whether the MPPT needs the battery to be essentially flat to correctly identify voltage, or whether a partial charge is fine.

Also @OffGridFreak — is that 100V input limit the absolute max, or is there a recommended operating ceiling below that? I've seen some advice suggesting you want a buffer below the rated VOC limit, especially on cold mornings when panel voltage spikes.