The shunt is in, the negative cable is landed on the right stud, and VictronConnect on your phone reports 13.4 volts and 82 percent exactly as it should. Over in the RoamVitals hub the device is there in the list, named and present. Behind the name there is nothing at all.
That is almost always one missing field rather than anything wrong with the install. Victron gear broadcasts its state continuously over Bluetooth, a feature they call Instant Readout, and it goes out encrypted per device. Until the hub holds that particular device’s key it can hear every broadcast and turn none of them into numbers. Copying the key across takes about a minute, once you know which screen it hides behind.
Encrypted, and reasonably so
It is easy to read the encryption as Victron making life difficult, so it is worth a moment on why it is not. A broadcast goes out to everyone in range unconditionally, the same way a Govee puck shouts its temperature at anybody who cares to listen. The difference is what is in the shout. Your state of charge, your draw, whether anyone is home. Thirty feet from the next rig in a full campground that is nobody’s business but yours, and encrypting it per device is the defensible call rather than an inconvenience somebody inflicted on you.
The key stays yours, too. The device generates it, VictronConnect shows it only to somebody who can already connect to that device, and handing a copy to us is a decision you make one device at a time.
Where it lives in VictronConnect
Phone in hand, standing next to the thing, it goes like this.
- Open VictronConnect and connect to the device over Bluetooth the way you normally would.
- Go into that device’s settings, then into Product Info.
- Find Instant Readout Details. Before you copy anything, check that Instant Readout is switched on, because some firmware ships with it off. A device with it disabled is broadcasting nothing whatsoever, and no key decodes a broadcast that never happened.
- Read off the encryption key, sometimes labelled the advertisement key. It is a long hexadecimal string.
- Put it into the RoamVitals hub against that sensor, all of it, right through to the last character.
That last point sounds like padding and is not. The string is long, phone clipboards truncate, and a key missing its final two characters looks precisely like a key that was wrong from the start. If there is any doubt, retype it and compare both ends against the app.
Every device has its own key. A SmartShunt and a solar charger in the same bay do not share one, and there is no master key for the rig. Doing several means doing them one at a time and labelling as you go, because a wrong key throws no error anywhere. What it gives you is a sensor sitting there quietly decoding nothing, which looks identical to one that is simply out of range.
What the shunt actually tells you
With the key in, a SmartShunt or a BMV battery monitor gives up four readings. Voltage, which you probably had already. Current with a sign on it, so charging and discharging are told apart rather than guessed at. Power. And battery level, a genuine state of charge counted in and out of the bank rather than inferred from a voltage that sags under load and recovers the moment you stop drawing. That last one is the whole reason to fit a shunt instead of a voltmeter, and the battery guide goes into why voltage alone will never quite get you there.
The rest of the range: recognised, not decoded. Solar chargers and DC-DC converters broadcast Instant Readout too, and the hub sees them sitting on the air, but their record layouts are not decoded yet. They turn up as a device we know is there with nothing useful behind them. We would rather say that plainly than claim the whole Victron range on the strength of the part that works.
Still nothing behind the name?
Work down in this order, because the first one accounts for most of it. Confirm Instant Readout is actually enabled on the device, since it is off by default on some firmware and no key will rescue a device that is not broadcasting. Then satisfy yourself the key is the whole key, retyping rather than pasting if a phone clipboard was anywhere in the chain. Then check it is the right device’s key at all, which is easy to cross when two Victron products share a bay and both keys open with the same handful of characters.
If the device is a solar charger or a DC-DC converter, stop there. The key is fine, the hub can hear it, and there is simply nothing decoded behind it yet. Past that point you are looking at range rather than keys, and a battery bay tends to be the far end of the rig behind a metal wall, which is a different problem.
One bit of good news to finish on. Updating VictronConnect regenerates nothing, and neither does a device firmware update, so a key you saved two seasons ago is still the key today. The one thing that will change it is a factory reset, and if you ever do that, expect to come back here.
