The Victron VE.Bus Smart dongle, the VE.Direct Bluetooth Smart dongle and the MK3-USB interface fill the gap for Victron products without built-in Bluetooth. They connect older or non-Smart gear to the VictronConnect app. They look similar but work with different ports, so buying the wrong one is a common mistake. Here’s which one you need.
Victron Dongles Compared
| VE.Bus Smart dongle | VE.Direct Bluetooth Smart dongle | MK3-USB | |
|---|---|---|---|
| Port | VE.Bus | VE.Direct | VE.Bus |
| Connects to | Phone or tablet (Bluetooth) | Phone or tablet (Bluetooth) | Computer (USB) |
| Works with | Multis, MultiPlus, MultiPlus-II, Quattro, VE.Bus Phoenix inverters | BMV-70x, VE.Direct MPPTs, VE.Direct Phoenix inverters | VE.Bus inverter/ |
| Instant Readout | Yes | Yes | Wired Instant Readout |
| Extra | Voltage and temperature sense | None | Full configuration with VEConfigure |
Sources: Victron VE.Bus Smart dongle and VE.Direct Bluetooth Smart dongle product pages; MultiPlus-II 2x120V manual; VictronConnect manual.
Victron VE.Bus Smart Dongle
Victron calls it “two products in one”:
- Bluetooth for inverter/chargers. With VictronConnect, you can monitor the unit, change the input current limit, and switch between Off, On and Charger-only.
- A voltage and temperature sensor for the inverter/charger, which works with all models.
It also adds Instant Readout, which shows key data, warnings and errors in the VictronConnect device list. Victron suggests it for caravans, smaller yachts and motorhomes where a GX device is more than you need.
VE.Direct Bluetooth Smart Dongle
This dongle reads any product with a VE.Direct port, such as BMV-70x monitors, BlueSolar MPPTs and VE.Direct Phoenix inverters. It shows battery status and solar power on your phone, with Instant Readout as well. If your MPPT is a SmartSolar, it already has Bluetooth and you don’t need this.
MK3-USB
The MultiPlus-II manual lists an MK3-USB interface and an RJ45 UTP cable as the hardware needed to configure the unit. The MultiPlus-II datasheet says VEConfigure needs a computer and an MK3-USB interface. The VictronConnect manual notes that while you’re connected through an MK3, communication with a GX device is blocked, so unplug it when you’re done.
Which One Do You Need?
- A MultiPlus or Quattro with no GX device: VE.Bus Smart dongle.
- A BlueSolar MPPT or BMV-700/702: VE.Direct Bluetooth Smart dongle.
- Advanced inverter/charger settings, or parallel and three-phase setup: MK3-USB.
Good to Know Before You Buy
- Bluetooth range is short.
- No remote access. For VRM, use a GX device.
Full specifications for the VE.Direct Bluetooth Smart dongle are on Victron’s product page.
For the complete spec sheet and current manual, see the Victron VE.Bus Smart dongle page.
Worked Example: Three Common Setups
A van with a MultiPlus-II and a BlueSolar MPPT, no GX device. The MultiPlus-II needs a VE.Bus Smart dongle for app control and monitoring, and the BlueSolar MPPT needs a VE.Direct Bluetooth Smart dongle. That’s one of each, and both show up in the same VictronConnect device list.
A boat with a SmartSolar MPPT, a SmartShunt and a Phoenix VE.Direct inverter. The SmartSolar and SmartShunt already have Bluetooth. Only the Phoenix needs a VE.Direct Bluetooth Smart dongle.
A home system with two MultiPlus-IIs in split-phase and a Cerbo GX. The Cerbo connects to the VE.Bus and VE.Direct devices with cables and handles monitoring and VRM. An MK3-USB is still useful for the initial split-phase configuration with VE.Bus Quick Configure.
When a GX Device Replaces the Dongles
A Cerbo GX or Ekrano GX connects to VE.Bus and VE.Direct products with cables, so in a system with a GX device you often don’t need dongles at all. The GX gives you the Remote Console, VRM remote monitoring, alarms and history, and VictronConnect can reach many connected devices through VRM. Dongles make the most sense in small systems where a GX would be more than you need.
| Need | Dongle | GX device |
|---|---|---|
| Local app control | Yes | Yes |
| Remote access over the internet | No | Yes, through VRM |
| Long-term history | Limited | Yes |
| Multiple devices on one screen | Device list | Full system overview |
Setup Steps for the VE.Bus Smart Dongle
- Plug the dongle into a free VE.Bus port on the inverter/charger with an RJ45 UTP cable.
- Connect its voltage-sense wires to the battery and fit the temperature sensor on the battery’s negative terminal, if you’re using that feature.
- Open VictronConnect and find the dongle in the device list.
- Pair it using the PIN printed on the label, then change the PIN to your own.
Setup Steps for the VE.Direct Bluetooth Smart Dongle
- Plug it into the device’s VE.Direct port.
- Open VictronConnect; the device appears in the list.
- Pair with the default PIN and set a new one.
Using the MK3-USB With VictronConnect
VictronConnect on a Windows or macOS computer, and on Android with a USB OTG adapter, can use an MK3-USB to configure a VE.Bus product without Bluetooth. That’s handy on a bench before installation, and for saving a backup of the unit’s settings.
Quick Buying Checklist
- Find the communication port on your product: VE.Bus (RJ45 on inverter/chargers) or VE.Direct (small 4-pin port on MPPTs, BMVs and Phoenix inverters).
- Check whether it already has Bluetooth; Smart-branded products usually do.
- Decide whether you want local app access only (dongle) or remote access and history (GX device).
- For full inverter/charger programming and Assistants, add an MK3-USB.
Instant Readout Explained
Instant Readout shows key data, such as battery voltage, solar power or charger state, directly in the VictronConnect device list without opening a connection. It’s a quick way to check several products at a glance, and the dongles add it to products that don’t have Bluetooth built in.
FAQ
Does the Victron VE.Bus Smart dongle work with a MultiPlus-II?
Yes. Victron lists MultiPlus-II among the supported inverter/chargers.
Do I need a dongle for a SmartSolar MPPT?
No. SmartSolar models have Bluetooth built in.
Can I program a MultiPlus-II with just the dongle?
For full configuration in VEConfigure, Victron specifies an MK3-USB.
Can I use one dongle for two devices?
No. Each dongle connects to one product’s port. A GX device is the way to bring several devices together.
Do Smart products still need a dongle for Instant Readout?
No. Products with built-in Bluetooth, such as SmartSolar MPPTs and SmartShunts, support Instant Readout on their own.
Sources: Victron VE.Bus Smart dongle and VE.Direct Bluetooth Smart dongle product pages; MultiPlus-II 2x120V manual (configuration) and datasheet; VictronConnect manual, victronenergy.com, accessed Oct 2026.
Related: EcoFlow Delta 3 Max App Guide, EcoFlow Delta 3 Max Offline Without Wi-Fi, EcoFlow Delta 3 Max RV Boondocking, plus the Victron Energy Guide