Install Quatro in a way that does not need G99 or G100/2

Been down this rabbit hole on the boat — if your Quattro is purely island mode with no grid-tied export, you're essentially invisible to the DNO and G99/G100 becomes someone else's problem, not yours.

The trick is keeping the AC input firmly on the "generator" side of things rather than anything that looks like a grid connection — Victron's own architecture actually makes this fairly clean if you're disciplined about it.

My setup has the Quattro sitting between my Fogstar lithium bank and a dedicated consumer unit that's completely isolated from the grid supply coming into the boat's shoreline. Grid power charges the batteries through the inverter/charger, never bypasses it, and nothing exports back — DNO can't touch you if there's no parallel operation.

The grey area is if you've got solar feeding in as well — even with a Sofar on a separate string, the moment anything could theoretically backfeed through a sequence of failures, you're arguably back in scope.

Anyone else running a similar topology with PV in the mix and managed to keep it genuinely outside G99 territory without relying on a load of "trust me bro" logic in the design? Curious whether the transfer switch approach some folks use actually holds water with a pedantic DNO.

@WheresMeWires87 this is exactly how I've got my van setup running — pure island mode, no grid connection whatsoever, so the whole G99/G100 conversation simply doesn't apply.

The moment you introduce a shore power input though, even if you're never exporting, you're potentially back in murky territory depending on how your installer interprets the regs. Worth being crystal clear about that distinction.

My Victron Quattro sits happily behind my Fogstar lithium bank, inverting away, completely off-grid. Nobody from the DNO is ever going to knock on my van door asking questions. The isolation is the whole point — it's freedom by design, not a workaround.

@WheresMeWires87 @CoastalCamper solid points both of you. Worth adding that on a boat or van this is fairly straightforward, but if you're doing a static off-grid install at a property, it's still worth checking your buildings insurance small print — some policies get funny about inverter/charger installs regardless of whether the DNO is involved. The Quattro itself doesn't care either way, it's just running as an islanded system. The G99/G100 headache only really materialises the moment you contemplate a grid connection or export, so as long as you're genuinely committed to staying off-grid, you're in clean water. Keep your system documentation tidy though, just in case anyone ever asks questions down the line.

@WheresMeWires87 just don't accidentally leave shore power connected when the marina sparky comes snooping — your "island mode" defence evaporates faster than my motivation to read the G99 documentation properly.

@WheresMeWires87 good shout, and worth clarifying for anyone reading who's considering this on a static installation — the moment you've got any kind of grid connection point, even just an inlet socket for occasional shore power top-ups, you're in murkier territory. The DNO don't necessarily care about your intent, they care about the physical possibility of backfeed. On a boat or van with genuine islanding it's clean and simple, but I've seen people try to replicate this logic on domestic installs and convince themselves they're exempt. They're not. G99/G100 exists precisely because "I'll never export" isn't something the network can verify. Keep it genuinely isolated, document your setup properly, and you'll sleep easy. @HalfAJob55 raises a fair point about shore power too — that cable is a liability if someone starts asking questions.

@BenChapman67 raises the crucial distinction. On my narrowboat the Quattro sits in pure island mode — shore power charges the batteries via the transfer switch, full stop. Nothing ever flows back toward the pedestal. Victron's own PowerControl and PowerAssist functions are configured specifically to prevent that reversal.

What people sometimes miss is the input current limiter setting. If you cap that correctly in VEConfig, the unit physically cannot push back upstream even if something glitches. It's not just a software promise — it's how the topology works.

My static caravan backup setup is different story entirely; that does have a grid connection worth declaring. Two very separate conversations with two very separate paperwork trails. Conflating them is where people get into trouble with their DNO.