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ilpowerdevision avatar image
ilpowerdevision asked

Error #67 (BMS connection lost) on VE.Direct-MPPT

Error #67 "BMS connection lost" for no apparent reason.

It looks like there is a bug in CerboGX (v1.94 and v1.93) or MPPT 150/35 (v.1.61) software. Hard reset or soft reset on CerboGX fixed it for me too (for a short time).
- 2x Pylontech us5000c
- 1x Cerbo GX (v2.94 and now v2.93 testet)
- 2x BlueSolar Charger MPPT 100/20 48V (v1.61)
- 2x BlueSolar Charger MPPT 150/35 rev3 (v1.61)


1. How to downgrade BlueSolar Charger MPPT from v1.61 to an older version?
2. How to downgrade Cerbo GX to an even older version than (v2.93)?

MPPT Controllerscerbo gxBMSPylontech
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8 Answers
Paul B avatar image
Paul B answered ·

usually means that the cerbo can no longer see the bms usually cause by incorrect setup of some type. best to contact the battery or bms supplier

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ilpowerdevision avatar image ilpowerdevision commented ·

yes it is the following interface:
CerboGX <-> MPPT-Charger <-> BMS (Pylontech).


The only thing that has changed is the software of the CerboGX and the MPPT-Chargers. Therefore the question about 1. and 2. (see above).

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bees avatar image
bees answered ·

I had the same issue after upgrading to a 2nd Multiplus 5kva and installer upgraded all firmware. I’m not sure what the firmware versions were on the MPPTs but the Cerbo was on 2.82 and is now on 2.94. MPPTs now on 3.13. Running 6x Dyness B3 batteries (similiar to Pylontech and looks like it’s mostly them getting these issues).


Installer came out to do hard reset on the MPPTs so it can pick up the BMS, but it still didn’t work.


I started looking around and found a ‘Battery Monitor’ under Devices in VRM that was unavailable and last seen just before the firmware upgrades. I suspect this is how the Dyness batteries connected to the system originally. After the firmware upgrade the batteries probably were seeing the system via another means (noticed I can now see decimals of battery remaining, before you could only see 99, 98, etc, now it shows 98.5 etc). This made me think that the MPPTs might be looking for this Battery Monitor that wasn’t available anymore. I then removed it, rebooted the Cerbo, then went into the MPPT settings under Networked Operation, and reset the BMS comms there. After I done that error 67 disappeared and system started generating again.


Hope this helps someone down the line.

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ilpowerdevision avatar image ilpowerdevision commented ·

Thanks! Unfortunately, it didn't help here.

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ilpowerdevision avatar image
ilpowerdevision answered ·

The only solution is to constantly restart the CerboGx. Please help (need old Software for MPPT and CerboGX for check an probably solve)..

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rotevery avatar image rotevery commented ·

You may need to disable BMS control everywhere and disconnected the BMS cable from your Victron system as a temporary fix. Reset your MPPTs and get them to operate without BMS control. Disable BMS Control and BMS battery measurement in the several places in Settings on the Cerbo GX and also in the Quattro or Muliplus or equivalent (via VEConfigure 3 or Remote VEConfigure). Take note of the settings in the BMS and use those to do settings in the MPPTs, Inverter and DVCC in Cerbo GX. Hopefully you have smartshut or BMV or you can use the inverter (e.g. Quattro) as battery monitor. This is a temporary fix while you troubleshoot and find the cause of the lost BMS connections.

I'm having the same problem with my newly / first-time connected Felicity Solar BMS which I just connected today (yes I know not on the compatibility list but Felicity Solar have an interface Com-Box that makes FS BMS work with Victron system). Above suggestion is what I've done (in my own case, basically revert to what was working like you are trying to do but I can't answer how to revert to older firmware versions like you are asking). In my own case I'm suspecting the FS BMS and FS is working with me to resolve (happy about their great technical support). Reason is that the FS BMS is reading voltage double the actual value and current half the real value.

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nickdb avatar image
nickdb answered ·

As I understand it, the behaviour hasn't changed, just a specific error message has been generated to explain why it is behaving the way it is.

The system has always behaved this way if the GX or BMS is disconnected for long enough to time out. Just previously it would have moaned about low voltage and then fallen over.

Probably why a reboot works temporarily.

You need to try eliminate if it is a cable issue.

There was a CAN issue addressed in 2.94 Venus code, presume you have tried this?

You need to try troubleshoot what is disappearing, is it the GX connection to the MPPT, is it the BMS to the GX.


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h8mecz avatar image
h8mecz answered ·

Does the downgrade of FW of Cerbo or MPPTs help to solve ERROR 67? thanks guys for your feedback.

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Alexandra avatar image Alexandra ♦ commented ·
@H8meCZ

No it does not.

Remove the comms cable. Reset to factory defaults.

Resetting to factory defaults (then reprogramming with charged voltages chemistry etc) will allow it to work in stand alone mode.

The real problem is comms were lost so if you solve that issue, the problem will also go away.

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h8mecz avatar image
h8mecz answered ·

I have tried cable B, cable A - the same problem. Still occours, very randomously. When I have powered Cerbo from battery and everything else is off - it works without any issue. When I turn on the PV - problem appears.

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towatai avatar image
towatai answered ·

is your bluetooth ve-smart networking active and your mppt integrated there or even the master? I have for some time sporadically similar problems and have my system several times completely torn apart and completely rebuilt from scratch and set. for a few days I have the ve.smart networking times deactivated and so far no "error 67" from my two MPPTs and / or the smart shunt.

this problem seems to have quite a few people if you read through this and other forums.

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perry-westphal avatar image
perry-westphal answered ·

I solved this issue last month.

To simulate the problem:

Disconnect all mppt´s and repower CERBO.

When connecting a mppt, the cerbo immediately goes into error 67 (BMS connection lost)

Solucion: Replace CERBO

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