Victron Orion TR Smart non-isolated DC to DC charger 12-12- 30 Amp making weird static/buzzing sound

Had something similar with my Orion-Tr Smart 12/12-30 a while back — that particular buzzing/static sound is genuinely unsettling when you first hear it, especially because mine was doing it even when the unit shouldn't have been doing anything active.

Worth checking a few things:

Is the sound coming from the unit itself or the wiring nearby?
Mine turned out to be the DC cables vibrating against the van chassis when current was flowing. Wrapped them in split loom and the worst of it disappeared overnight.

The "off but still buzzing" thing — this caught me out too. The Orion-Tr Smart draws a small standby current even when the output stage is idle. If your leisure battery voltage is sitting close to the input threshold, it can apparently cause the internal circuitry to cycle in and out, producing that horrible static-like noise. Firmware update sorted mine, so worth checking VictronConnect to see if you're on the latest version.

Also check your grounds. A poor chassis ground or a floating negative somewhere can create all sorts of audible interference with switching regulators like this. I run dedicated negative cables back to my battery bank rather than relying on chassis grounding and it made a noticeable difference.

The Orion series are brilliant units overall — mine's been charging my Fogstar Drift 100Ah without complaint for over a year now — but they're not immune to installation gremlins.

Anyone else on here experienced the cycling/standby noise issue specifically? Curious whether it's more common on the non-isolated versions or whether the isolated 30A units have the same quirk.

@Chippy the Orion-Tr Smart 30A does have a characteristic high-frequency switching noise — completely normal operation. The inductor coil whine is particularly noticeable when it's working hard at partial load, ironically less so at full load.

Few things worth checking though:

• Mounting surface — metal panels act like a sounding board and amplify it massively. Rubber isolation mounts help enormously
• Input voltage — if your starter battery is sitting low, the converter works harder and the pitch changes noticeably
• Firmware — Victron pushed an update a while back that adjusted the switching frequency slightly

Had mine in a timber-framed tiny house build, barely audible. Friend has the same unit hard-bolted to a steel bulkhead on his boat and it sounds like an angry wasp.

If it's genuinely static rather than a tonal whine, I'd raise a warranty query with wherever you purchased it.

Interesting one this — did either of you notice whether the pitch of the buzzing changes depending on the charge current being drawn? Mine did something similar on my shepherd's hut setup and I found the noise was noticeably different when the Orion was working hard versus just trickle charging. Makes me wonder whether it's worth checking the input voltage too — if the alternator output is fluctuating, could that affect how the unit sounds? Also curious whether it's mounted on a solid surface or something that might be resonating? On the boat I found a bit of vibration transfer from the hull made everything sound much worse than it actually was. What's it mounted on?

@CornishBoater yes, absolutely — mine would shift pitch noticeably as the current ramped up during bulk charging. Almost like a tiny electric motor changing load. Took me a while to figure out the pattern.

What I'd actually watch for is when it buzzes. My Orion in the cabin was silent at low input voltages, then started singing properly once the leisure battery bank dropped below a certain threshold and the charger worked harder.

If yours is buzzing constantly even at float or with a nearly full bank, that's worth investigating further. A quick check of your cable gauges and connections is always worth doing first — undersized wiring causes all sorts of odd harmonic nonsense with these switching chargers. Victron's own guidance suggests going beefy on the cable runs, and they're not wrong.

@MountainBarry that's a really useful observation — so it tracks with the charge curve rather than being random? I'm wondering whether the pitch/intensity also changes based on what's happening at the battery end? Like does the state of charge of the receiving battery influence it at all?

I've got a Fogstar Drift 100Ah on the output side of mine and I think I noticed the tone was slightly different when it was deeply discharged versus nearly full — but I wasn't paying close enough attention to say for certain.

Has anyone actually measured the frequency with a phone app or anything? Would be interesting to know if it's consistently in a specific range across different units, or whether it varies unit to unit. Might help distinguish "normal switching noise" from "something worth flagging to Victron support."

@Cleggy exactly right — it tracks the charge curve precisely because what you're hearing is the switching frequency of the converter interacting with the magnetics inside. The Orion-Tr Smart runs a high-frequency switching topology, and under certain load conditions the inductors and transformer laminations can physically vibrate. Completely normal behaviour, even if it sounds alarming.

My 12/12-30 does this when ambient temperature is low — the components are slightly stiffer mechanically and resonate more readily. Once it's warmed up after 10-15 minutes the sound typically reduces noticeably.

Worth confirming though: if the buzzing is accompanied by heat beyond the normal warm-to-touch range, or the unit's throwing fault codes on VictronConnect, that's a different conversation entirely. But pitch-shifting buzz that correlates cleanly with the charge curve? Almost certainly just acoustic noise from the magnetics rather than anything actually wrong.

@TorJake so the switching frequency is literally audible? That's what I want to understand better — is this just a characteristic of all Victron Orion-Tr units or is it more pronounced on certain firmware versions?

Asking because I've got one in my static caravan setup and mine does make a faint noise but I honestly couldn't tell you if it's normal or the early sign of something going wrong.

Does it matter whether it's isolated vs non-isolated? I've only got the non-isolated version so wondering if that changes anything.

And the bigger question — does it actually cause any harm or is it purely cosmetic/acoustic? If it's benign I'll stop losing sleep over it but if it points to component stress or early failure I'd rather know now.