Inverter RS Smart Solar pv input current

Been tinkering with my setup on the narrowboat this weekend and stumbled into something that's been nagging at me — has anyone else noticed what looks like a discrepancy in the Inverter RS Smart Solar manual around the PV input current ratings?

Not talking about the Multi RS here, strictly the Inverter RS Smart Solar variant.

I was trying to work out whether I could safely add another couple of panels to my existing array, and when I cross-referenced the manual figures against what the unit actually seems to handle in practice (monitoring via the Victron app), something didn't quite add up. The stated maximum PV input current in the manual felt inconsistent between different sections — like one section was giving me a different number to the specs table.

Could be user error on my part, I'll fully admit that 😅 But I wanted to ask:

• Has anyone else spotted what might be an error or outdated figure in the current manual?
• Is there a more reliable source for the actual safe operating limits — maybe a Victron datasheet or somewhere on the Victron community forum?
• Does anyone have this unit running a decent-sized array in the UK and found real-world limits that differ from what's published?

I'm running Fogstar cells in a 24V bank and would love to push more solar into the system, especially through these grim winter months when every watt counts. Just want to make sure I'm not going to fry anything before I commit to buying more panels.

Anyone with hands-on experience of this specific inverter, please chip in — genuinely helpful to hear what others have found.

@ThingamyBob yes, ran into exactly this on my motorhome build last summer. The Inverter RS Smart Solar reports PV input current differently depending on whether you're reading it through VictronConnect versus the GX device — they're pulling from different data sources internally.

What caught me out was assuming both figures should match. They don't always. The GX polls the device at a slightly different interval and can show averaged values rather than instantaneous ones.

Worth checking:

• Are you comparing figures from VictronConnect vs Cerbo/Venus?
• What firmware version are you on?

Mine settled down after updating to the latest firmware — there was a known rounding/reporting quirk in earlier versions. Fogstar cells behave themselves, but the displayed current was making me think my panels were underperforming when they absolutely weren't. Classic case of trusting the monitoring over the actual output.

@ThingamyBob the RS Smart Solar measures PV current before the internal MPPT conversion losses, so what you're seeing on the input side versus what actually hits your batteries is basically physics doing its usual unhelpful thing — welcome to the Victron rabbit hole, population: all of us on boats who thought we understood electricity.

What @VoltFiona said tracks with what I've seen messing around with mine for the garden office. Worth also checking your VRM dashboard — sometimes there's a slight lag in the reported figures versus real-time, which can make the numbers look more "off" than they actually are. Pulled my hair out over this for a week before I realised it was just a display timing thing rather than an actual measurement error. If the discrepancy is consistent rather than flickering about, that's when I'd start digging deeper into the MPPT settings.

@VoltFiona is right but nobody's mentioned the obvious gotcha — that "discrepancy" gets worse when your panels are cold and cranking high Voc, because the RS is measuring raw string current which doesn't map cleanly to what your battery side actually sees after the MPPT does its voltage conversion magic. Been catching this on my narrowboat all winter with Victron's own VRM portal showing numbers that'd give you a headache if you took them at face value. Check your actual watt figures rather than obsessing over the amps — watts don't lie, amps absolutely do when there's a voltage transformation happening between measurement points.