Connect Cerbo GX to MPPT solar

Been running a similar setup in my motorhome for a couple of years now — two Victron SmartSolar MPPTs both feeding into a Cerbo GX — so this topic is right in my wheelhouse.

The VE.Direct to USB route works fine in principle, but cable routing is where it gets messy in practice. Running multiple USB adapters round awkward corners in a van is already annoying enough; I imagine on a boat it's considerably worse given the moisture exposure and the longer cable runs involved.

What I'd actually recommend looking at instead:

• VE.Direct cables directly into the Cerbo GX — the Cerbo has four dedicated VE.Direct ports, so with two MPPTs you don't even need USB adapters at all. Direct connection is cleaner, more reliable, and eliminates a potential failure point.
• Keep cable runs under 10 metres — Victron's spec allows up to 10m on VE.Direct, which should be sufficient for most installations unless you're on a larger vessel.
• Cable conduit or trunking — for a permanent installation I ran mine through some split conduit secured with adhesive cable clips. Keeps everything tidy and protected.

The USB adapter approach makes more sense if you've already used up your VE.Direct ports with other devices (BMV battery monitor, for instance), but even then a USB hub adds another layer of complexity that I'd personally avoid if at all possible.

Anyone else running dual MPPTs into a Cerbo? Curious whether others have had issues with the USB adapters dropping connection intermittently — I've seen a few reports of that online and it's partly why I went direct VE.Direct from the start.

@Liam1990 VE.Direct cables are the way unless you enjoy the special kind of chaos that comes with USB hubs on a moving vehicle hitting every pothole on the A38.

@ThistleVicky is right about the USB hub nightmare — learned that the hard way on a bumpy B-road in Scotland.

One thing worth adding: if you've got two MPPTs, Victron's VE.Direct to USB interface only gives you one port per adapter. The Cerbo has two dedicated VE.Direct ports built in though, so just run direct cables to each controller and skip the USB route entirely.

Also make sure you're on the latest firmware on both the Cerbo and the SmartSolars — there were some older versions where the MPPT data would drop off the dashboard randomly. Victron Connect makes updating straightforward enough.

Once it's all talking properly, the Cerbo dashboard gives you per-controller yield data which is genuinely useful for diagnosing shading issues on individual arrays.

@CaddyProject a bumpy B-road in Scotland is basically a USB hub stress test that no QA department would survive.

Running twin SmartSolar 100/20s into my Cerbo via VE.Direct and the whole setup's rock solid — the Victron Connect app just sees everything without a fuss, which still feels like witchcraft after years of bodging things together.

One thing worth adding: label your VE.Direct cables before you route them or you'll spend a deeply spiritual afternoon in your cabin wondering which MPPT is which on the GX Touch screen.

@Mel1980 😂 accurate

Worth mentioning — if you're going the VE.Direct route, the Cerbo has 4 VE.Direct ports built in, so no hub needed for most setups. Just run cables direct and you're sorted.

I charge my EV from the system too, and having both MPPTs visible in the Cerbo dashboard is genuinely useful for monitoring whether there's enough solar headroom before kicking the charger on. Makes a difference when you're trying to squeeze every kWh out of a cloudy UK afternoon.

One thing I'd double-check — make sure your VE.Direct cables aren't routed near any inverter cabling. Picked up some nasty interference that way initially. Took me ages to track down.