I’m almost inclined to say that this is a bug, specifically to the MKII, but the fact that it works with older Cerbo devices is what makes it a bit weird. You could step back to version 3.55 to see if that work, but it that also fails. Then it could potentially be a hardware failure🤷♂️
What kind of BMS do you have? Can’t you use the BMS Can port? Perhaps not due to an unsupported transmission speed?
Hi ChiefSolar
I agree with you, I believe it is a bug in firmware or a hardware issue with the Cerbo.
I have been working on this issue for a couple of months now.
All my testing indicates that it is either a firmware or hardware problem.
The seller and the distributor have not been able to resolve the problem.
I have the latest JK V19 BMS.
I am not sure what you mean by this
Blockquote
Can’t you use the BMS Can port? Perhaps not due to an unsupported transmission speed?
Blockquote Can’t you use the BMS Can port? Perhaps not due to an unsupported transmission speed?
What country are you in ?
Having read all the diagnostics you did: most likely its a hardware failure of the Cerbo GX MK2.
I recommend to get a new one under warranty.
Could you tell me the serial number once RMAd?
Thanks, Matthijs
*Hi Matthijs Thank you for the reply… I agree.
The serial number is: HQ2447GU697
Getting a new one is easier than done. I have lodged at least three support requests, and have several emails from the distributor over two months, with no solution.
I’ll look into that, find one of them (using the serial number) and prompt a response
Serial number: HQ2447GU697
Country: Australia
City: Gooburrum
Tested: yes system
Description of failure: Inverter will not turn back on after shut down.The VE Bus cable must be removed before the inverter will turn back on. A VeConfig file can be downloaded and edited, it can be sent back to the inverter, but after the change is made and the inverter shuts down, it will not restart until the VE cable is removed,
First installation date: 2025-05-14
Date of failure: 2025-05-14
Installed firmware version: V3.63
Installation: self installed
Desired solution: Please replace with new Cerbo or supply new firmware to fix the issue.This issue has been outstanding now for several weeks, and Victron do not appear top be assisting to get the issue resolved. I have sent videos of the issue to the seller.
Aha. I took my JK V19 BMS and that won’t seem to work on 250 kbit/s but this one worked for me:
I have the same problem with the same setup:
Multiplus II 5KVA, Cerbo GX MK2 and JKBMS v19. And a MPPT450.
On mye two other systems (Multiplus II 5KVA, Cerbo GX , pylontech , mppt450) it works OK.
I have also tried different cables, with or without termination etc
Interesting. Also after a firmware upgrade or not? In case that’s a yes, then downgrade to a version that worked and wait for a fix. That is. If this is a software bug of some sort.
Hi Bluey, I have a similar set up with Cerbo GX, Mk2, Quattro 8kva & RS450 MPPT. I thought it was just me and poor wifi to the Cerbo or some thing and i just unplug every time same as you but a bit annoying. Cheers
I also have a testsystem with a Cerbo GX MK2, Multipluss-II 48/3000 and a JK-BMS v19.4
This works fine and I do not need to disconnect the cable to switch off/on the inverter.
I will take my “test” Cerbo GX MK2(with cables an terminators) to my summerhouse this weekend and test it on my production system…
TEST - works fine
Cerbo GX MK2, v3.63 , HQ2352R2RMT
MultiPlus-II 48/3000/35-32 (ACOut2 switchable), fw 2629556, HQ2242YMHDX
Leaf #2, Generic Can-bus BMS battery JK-BMS, v19.4
Production - Cerbo GX MK2 - Will not turn Inverter back on
Naustet
Cerbo GX MK2, v3.63, HQ2403NJA32
MultiPlus-II 48/5000/70-48, fw 2623556, HQ2348QWENU
Naust Leif #1, Generic Can-bus BMS battery, JK-BMS, v19.2
Ok thanks for the replies. So that makes at 3 reported faulty units of Cerbo GX MK2.
I do have an update.
First to SolarChief downgrading to a previous version does not work
Actually it failed to load V3.55 firmware at all.
Second to stevenbushmarine and JFS jfstrand: How have the sellers responded to the issue with the Cerbo Mk2 issue?
The distributor has finally notified me that they are sending me a new Cerbo MK2.
I also performed a test with a seller whilst he was on the phone and he agreed that the
fault was exactly as shown in the video, and he thought it may be a faulty EEROM.
The test that was performed was to isolate the inverter (JK BMS V19) from the Cerbo and see it that solved the issue. I t did not fix the problem, but I did get a low voltage alarm and the inverter shut down, so that proved at least the the inverter/cerbo comms was working.
I hope now that VICTRON are reading these posts and take notice that there is a problen with the Cerbo MK2 and do something about it.
I have found so far that unfortunately the distributors and sellers do not have the expertise to solve these technical issues or my case any idea at all how to go about solving the problem.
From what I have heard VICTRON have no technical experts in Australia.
It is up to the sellers to fix the problems who are the the sales staff.
When I get the new Cerbo GX MK2 I will give feedback on the performance.
I have also sent a message and a link to the video to Johannes Boonstra
Sales Manager Victronenergy sales sales@victronenergy.com
He also makes a statement that Victron do NOT monitor this site.
I suggest you also send emails to him and advise him of the issue with the Cebo GX MK2, and maybe Victron will fix the problem.
Ok. That’s too bad. Thank you for letting me know. And while this is mainly a community driven forum, there are certainly cases where Victron folks interacted with their users and solved issues. However. It is normal for your reseller to be your main contact in case of hardware issues.
Solar Chief. That may be the case, but what do you do when you have a faulty Victron product, and you do NOT get the assistance to rectify the issue from the seller/distributor? There is no technical support in Australia from Victron.
Sorry. I cannot help you with that. Perhaps @guystewart knows what to do🤷♂️
Follow the support link in our guidelines, it will route the ticket to the responsible distributor. In most cases the reseller, especially if it was done online, have zero expertise or interest.
Hi Nick
The issue has had support tickets raised.
The seller was notified.
The distributor was notified and is aware.
The distributor has advised they are sending a new Cerbo, but I have not received it.
I will update when I connect the new Cerbo online.
Cheers
Hi.
I took my test Cerbo GX Mk2 and installed it on my “problem” system - with the same result. It still does not start with the cable inserted.
For me it seems that the problem is MK2 with a Multiplus-II 48/5000(fw 2623556).
In my testsystem the MK2 works OK with a Multplus-II 48/3000)fw 2629556)…
HI jfs That is very interesting.
Have you been able to get any response from Victron about the issue ?
I was also talking to an authorised Victron repairer, and he told me that there was an issue with the first batch of Cerbo GX MK2.
I have been informed that the distributor is sending a new Cerbo, but I have not received it yet.
I am disappointed that Victron have not picked up on this issue, and stepped in to resolve the problem.
