Cerbo GX MK3 vs MK2: what changed, and which one a boat needs

Victron's Cerbo GX now comes in two current versions, the MK2 and the MK3. From the outside you can't tell them apart: the MK3 has the same ports in the same places and runs the same Venus OS. What changed is inside — the processor — and that matters on some boats and not at all on others.

This page compares the two from Victron's datasheet and manual, plus hands-on reporting from Panbo, and sets out which boats need which. For the wider picture — what a Cerbo does, and how the MK2 differs from the original Cerbo GX — see Cerbo GX, MK2 and MK3 compared.

The short answer

• Same: ports, connectors, Bluetooth, WiFi, relays, inputs, power draw, size, mounting and software.
• Different: the processor — Victron says the MK3 is three to four times faster depending on load — and the VE.Direct device limit, 25 instead of 15.
• Buy the MK3 if you run Node-RED or Signal K server on the Cerbo, or connect many VE.Direct devices.
• The MK2 is enough for monitoring and controlling a typical boat's batteries, chargers, solar and inverter/charger, including DVCC.

Side by side

Victron publishes the two models on one datasheet with one set of port and electrical specifications; the processor and memory details come from Panbo's report on the MK3's launch.

What the extra speed is for

Most of what a Cerbo does on a boat — reading batteries, chargers, MPPTs and the inverter/charger, running DVCC, showing it all on a GX Touch and sending it to VRM — runs comfortably on an MK2. The MK3's headroom is for the optional software in Venus OS Large:

• Node-RED, for automating things: switching a relay on a battery state, logging, custom dashboards.
• Signal K server, the open marine data hub: anchor alarms, sending data to apps and chart plotters, and plugins.

Victron describes both as "resource intensive software applications relative to the CPU and memory of most GX devices", and warns that "if a GX-device runs out of memory or the load on the CPU becomes too high, the device will eventually reboot". A Cerbo that reboots also drops its battery monitoring, its DVCC control and its link to the BMS while it restarts — not what you want from the device coordinating your propulsion bank.

Panbo, which tested an MK3, found Node-RED loading noticeably faster than on an MK2 and "just as fast as the Pi" — Victron's Raspberry Pi build of Venus OS, the usual choice for people who outgrew a Cerbo. Panbo gives no benchmark figures.

Victron's Venus OS Large page still ranks the "Cerbo GX" as one model, second-fastest after the Ekrano GX; it doesn't yet separate the MK3.

Counting VE.Direct devices

Victron's limit is the total of VE.Direct devices connected directly and over USB — so three on the VE.Direct ports plus any on VE.Direct-to-USB cables. Victron says the limit "is mostly bound by CPU processing power", which is why the faster MK3 takes more.

Count yours: MPPT solar chargers, SmartShunts or BMV battery monitors, VE.Direct chargers and inverters. A typical cruising boat has a handful. If you're near 15, or plan to add solar controllers, the MK3 is the safer buy.

What doesn't change

Everything you wire to it. Panbo describes the MK3 as "visually indistinguishable from the MK2" with "no port changes", and Victron's datasheet gives both the same ports, electrical ratings and dimensions. In particular:

• Two VE.Can ports on both. The MK2 already fixed the original Cerbo's main limitation for boats: you can run VE.Can at 250 kbit/s and a BMS-Can battery at 500 kbit/s on separate buses. The MK3 keeps that.
• IP20 on both. Neither belongs in a damp locker or the engine space.
• 2.8 W on both, without a screen.

So an MK3 replaces an MK2 with the same cables in the same sockets.

Two things to know before you buy

Check the article number. The names differ by one digit and the boxes look alike. Victron lists the MK2 as BPP900450110 and BPP900451100, and the MK3 as BPP900451130 (its manual also gives BPP900450130 for the MK3).

Recovery works slightly differently. To reinstall Venus OS from a microSD card, the MK3 has to be started with the network button held down — "press and hold the network button, located directly above the power connector, while powering up the device. Without this, the Cerbo GX MK3 does not boot from the microSD card and the new image is not installed." Victron marks this step as MK3 only.

Not to be confused with "MK3" elsewhere in Victron's world

Victron uses "MK3" for something else too: the MK3 is the interface chip that talks to VE.Bus inverter/chargers. It appears in the MK3-USB interface used to configure a MultiPlus or Quattro from a laptop, and in Venus OS messages such as "GX Error #51 – mk3 firmware needs update", which Victron explains as the "MK3 controller inside the GX device" — the VE.Bus interface built into every Cerbo. Neither has anything to do with which Cerbo GX you have.

Which to buy

Prices vary by country and dealer, so compare current quotes.

Sources

Checked on 12 November 2026:

• Victron Energy — Cerbo GX & GX Touch datasheet: the MK3 speed claim, MK2/MK3 specifications, VE.Direct device limits and the note that they're "mostly bound by CPU processing power", article numbers
• Victron Energy — Ekrano GX, Cerbo GX, Nucleo GX manual: MK3 microSD recovery procedure and article numbers, VE.Can and BMS-Can rules, GX error #51
• Victron Energy — Venus OS Large: Signal K and Node-RED: resource use, the reboot warning, processor ranking of GX devices
• Panbo — "Victron unveils faster Cerbo GX MK3 and emergency reverse charging for Orion XS", Ben Stein, 2 October 2026: processors and memory of both models, identical ports, Node-RED experience

We are not affiliated with Victron Energy.

Related reading

• Cerbo GX, MK2 and MK3 compared — what a Cerbo does on a boat, and the original Cerbo's CAN limitation
• Motor drives on a Cerbo GX — putting the propulsion motor on the same screen
• Victron Lithium NG and the Lynx Smart BMS NG — the BMS a Cerbo coordinates
• Victron parts for an electric boat — mapping your spec to Victron hardware