Accuracy of the VRM app figures?

Been wondering about this myself lately. My Victron setup with a Multiplus-II shows consumption figures in VRM that I'm not entirely sure I trust 100%.

Anyone else cross-checked their VRM numbers against an actual meter or clamp meter readings? Curious how close people are finding them in practice.

From what I've read, VRM pulls its data from the CCGX/Cerbo calculations rather than direct metering at every point in the system — so there's potential for small discrepancies depending on where your shunts are and what's actually being monitored. If you've got loads wired in before your BMV shunt for example, they'll just disappear from the figures entirely.

My own setup isn't grid-tied so it's slightly different, but I do occasionally notice my Victron BMV-712 and my solar charge controller stats don't always add up perfectly over a week. Usually within a few percent, which I can live with — but it gets me wondering.

A few things worth checking if you're seeing bigger gaps:

• Shunt positioning — is everything flowing through it?
• CT clamp calibration on any grid meter inputs
• firmware — older Cerbo firmware had some known reporting quirks

Would love to know if anyone's done a proper side-by-side comparison over a month or so. And whether Victron's figures tend to read high or low compared to your supplier meter — that's the bit I'd genuinely find useful to know before trusting VRM for any serious energy budgeting. 👇

@VanAnne the VRM consumption figures are calculated rather than directly measured — it's essentially deriving load from the difference between what the MPPT/shore power is producing and what the battery shunt sees going in or out. That propagation of measurement errors can compound.

What transformed my confidence in the numbers was adding a Victron SmartShunt configured as a dedicated DC load monitor alongside my main battery shunt. Cross-referencing those two against a clamp meter on my AC distribution board revealed my VRM was consistently reading 4-6% low on consumption — likely down to a slightly miscalibrated shunt zero-drift.

Worth checking:

• Shunt tail current and charged voltage settings in VictronConnect
• Whether your Multiplus-II's AC sensor is properly configured
• VRM portal's advanced tab shows raw vs calculated values

For EV charging specifically, the inrush current can also fool the averaging intervals in VRM logging.

@VanAnne the dirty secret is that "consumption" in VRM is just solar + grid/shore - battery delta — so any inaccuracy in your shunt calibration multiplies straight through to the load figure, mine was reading 11% high until I re-did the zero-current calibration on the BMV-712 at genuine zero load (everything off, including the Multiplus standby draw). Cross-check with a proper clamp meter on your main feed if you want ground truth — a decent Fluke or even a cheap Uni-T will expose whether VRM is lying to you or your expectations are wrong. Spoiler: usually both.

@VanAnne had exactly this rabbit hole with my cabin setup last winter. The calculated consumption figure is only as accurate as your weakest sensor — and if you've got a SmartShunt that's been improperly configured (wrong battery capacity, wrong Peukert exponent) then the battery delta part of that equation is quietly lying to its face.

Worth checking:

• Tail current set correctly for your battery chemistry
• Charged voltage threshold appropriate
• Shunt wiring hasn't got any parasitic loads sitting on the wrong side of it

If you want actual measured load figures rather than derived ones, you'd need a proper energy meter on the AC output — Victron's own ET340 or similar. Adds cost but then VRM stops guessing and starts knowing.

Mine was consistently reading about 8% optimistic before I sorted the Peukert settings. Felt smug until I realised I'd been planning battery sizing around fantasy numbers. 🙄

Good points from everyone above. One thing worth adding — if you've got a Energy Meter (like a ET112 or ET340) on your grid connection, that'll give you directly measured import/export figures rather than calculated ones, which tightens things up considerably.

Also worth checking your MPPT settings if you've got solar — make sure the Multiplus-II and any MPPTs are all on the same VE.Bus/VE.Direct network and properly configured, as orphaned devices not reporting correctly can throw the whole calculation off.

@VanAnne the quickest sanity check is comparing your VRM monthly consumption total against your actual electricity bill if you're on hook-up regularly. That'll tell you fairly quickly how far off things are in practice. Mine was within about 3-4% once I sorted a rogue MPPT that wasn't being picked up properly.