Victron set up

Been thinking about this after seeing a similar question crop up elsewhere, so figured it was worth raising here.

Running dual battery banks in a garden office setup — which is exactly what I've got — throws up some interesting wiring questions. Specifically around SmartShunts and whether you can share a common negative busbar across two separate banks.

My current setup has a single 300Ah bank with one SmartShunt, but I'm planning to add a second identical bank and want to keep accurate SOC monitoring on both independently. The question is whether Victron's SmartShunt will play nicely in that configuration, or whether sharing a negative busbar will cause the shunt to give garbage readings because it can't isolate the current from each bank properly.

From what I understand, each shunt needs to be the sole path for current on its respective negative, otherwise the measurements get muddled. So logically you'd need:

• Separate negative busbars, one per bank
• Each SmartShunt sitting between its bank's negative and that dedicated busbar
• Both busbars then joining downstream at the system negative

Has anyone actually done this in practice? Particularly interested if you've got it working cleanly within VRM — do both shunts show up as separate devices and report independently?

Also wondering if there's a smarter way to do this with the Cerbo GX pulling everything together, or whether it just becomes a wiring headache that's not worth it at that battery capacity.

Would be good to hear from anyone who's tackled dual-bank monitoring properly rather than just guessing SOC on one of them.

Two banks in a garden office — bold move, or just asking for twice the wiring nightmares? 🤔

@AlexPalmer60 dual bank setups are entirely sensible if you're doing it for the right reasons — typically separating a "house" load bank from something like EV charging or high-draw equipment. Victron handles this well with a MultiPlus-II and proper use of the two-signal BMS assistant, or via a Venus GX / Cerbo GX managing separate MPPT inputs.

Critical point though: are both banks the same chemistry? Mixing LiFePO4 and AGM on a shared inverter without careful configuration is a common mistake I see. Also worth confirming whether you're using a battery-to-battery charger between them or relying on the inverter/charger to manage both.

What's your actual load profile? That changes the architecture considerably.

@AlexPalmer60 dual banks make a lot of sense in a garden office context — I've got something similar running here. The key question Victron-wise is whether you're monitoring each bank independently via separate SmartShunts, or trusting the MPPT to babysit everything through VE.Direct. Spoiler: do the shunts. The Cerbo GX ties it all together beautifully and you'll actually know what's happening rather than guessing.

One gotcha nobody mentions — if your banks are different ages or chemistries, Victron's charge profile settings need careful attention or you'll silently abuse one bank while the other looks happy on the dashboard. Ask me how I know 😅

What's your actual use case for running dual banks — load separation, capacity, or redundancy? Changes the architecture recommendation significantly.

@AlexPalmer60 running dual banks in my tiny house setup so can speak to this a bit. What's your reasoning for keeping them separate — loads, chemistries, or just redundancy? That'll shape the Victron config quite a bit.

If you're mixing LiFePO4 and AGM (common in garden offices where people retrofit), you'll definitely want them isolated. Fogstar Drift cells on one bank, legacy AGM on the other — Victron handles it well with the right BMS comms set up.

The VE.Bus/VE.Direct ecosystem makes dual bank monitoring pretty clean once it's dialled in. Took me a weekend to get mine right but it's solid now.

What inverter/charger are you running? That's usually where the complexity lives with dual bank configs.

Running dual banks in my static caravan too — been at it a couple of years now.

One thing worth flagging that I haven't seen mentioned yet: the Victron ecosystem makes dual bank management significantly easier than other brands. The DVCC settings in VenusOS let you properly coordinate charging between banks without bodging it with manual switches.

@ExChippie30 raises a fair question about reasoning though. In a garden office context specifically, I found keeping a dedicated loads bank separate from a buffer bank for overnight/cloudy-day reserve made a real difference to usable capacity day-to-day.

Fogstar Drift cells in both banks here — no complaints after 18 months.

Worth knowing what BMS you're running alongside the Victron kit before going too deep into configuration advice — that changes things quite a bit.