SOK data anomalies in VRM Victron

[Joske]

Hello Everybody,

Problem:
After spending hours or searching in my installation and online i am a bit lost. Cannot find the reason why this installation (I have multiplel installations working) keeps showing weird anomalies in the data charts of the Online VRM environment.
Anomalie like;
-SOK Cel voltage drop,
-SOK Pack voltage drop,
-SOK totaal SOC drop or spike.
All drops in different parameters drop in the same timestamp.

Setup:
8x SOK - SK48V100
3x Victron MultiPlus-II 48/8000/110-100 230V in 3 fase.
1x Victron Cerbo GX
2x Victron Lynx distributor
Touque: Everything is touquet to specification as described by the manufacturers SOK and Victron
Cable: CAN cables is self made because of the length (5 meters) and measured twice if its wired the right way.

Programmed:
SOK batterij interface selected: Victron

What i am thinking right now:
-is maybe the CAT cable for the CAN interface between the Cerbo en SOK has to be shielded. The reason why i did not change this s is because it is a hassle to change it and thought with the baute rate this can't be the problem. But may be i am wrong. Befor sombody jumps on this train.....

Questions:
1-Has somebody had the same problem?
2-And what else than the cable is probably causing this?
I would like for somebody to show me the right direction.

Cel-voltage drop:
Voltage pak drop:

Spike in SOC

 

[houseofancients]

@HighTechLab i know you've considerable testing with sok and Victron equipment..
Does this ring any bells ?

 

[HighTechLab]

This is usually a cabling issue…but you can try removing 1 battery from the chain at a time to isolate if there is a battery either reporting a wrong value or breaking the chain.

In one case a customers added a cat5 cable from the last battery to the first but I’m not sold on that idea.

 

[Adam De Lay]

My initial thought goes to the unshielded CAT cable. Possibly it's picking up interference from some other electrical device.

 

[Joske]

Everyone thanx for the comments

So… cable issues. It was a little part of me telling me this as i described.

Making a closed loop as @HighTechLab described is a good idea and fast to fix. And give an insight where the issue is located. Between de batteries or between the batteries and de cerbo. But maybe not the best, because it won’t solve the initial problem, I agree.
If that won’t solve the issue I am going to replace all the communication cables for shielded cables, just in case.

I will get back to this thread within a week to give everyone an update.

 

[HighTechLab]

Thank you!

 

[Joske]

Update: making a loop in the RS232 communication between the SOK batterys dose not solve the (my) problem. See print screen. In the next days i will attack the inverter/battery cable by crimping a new shielded communication cable and installing it. Will keep you updated

 

[Joske]

Update:
1- just in case, replaced all data communication cables in de RS485B and RS485C port with shielded CAT6 cables = No Effect
2- krimped a new data communication cable between SOK en Victron Cerbo GX with shielded CAT6 cable = No Effect
3- select an other masterbattery by selecting with the DIP switches and switch Bat-1 for Bat-2 and vice versa, programming the CAN port bij selecting Victron and using the new CAN port on the Bat-2= This worked, see print screen

Conclusion: Faulty CAN port

@HighTechLab -- But nou my conserns are on this internal BMS of the SOK battery,
A- is this BMS it working properley or is it isolated on/within the CANport?
B- if not, what is the effect on the rest of the pack?
C- and what are the test that i can do to verify that only the CANport is faulty and not the the rest of BMS??

 

[HighTechLab]

Yes, the CAN port is isolated - a completely different circuit than the RS485...so it really wouldn't hurt anything if you just used the CAN port of a different battery instead. You might ask your local SOK distributor for a replacement BMS and see what they say.

As far as testing to verify - run the system...trigger OVP and UVP; should prove that the BMS is operating. Based on the symptoms I wouldn't loose any sleep over it. In my experience, operational failures on these BMSs (that would lead to safety concerns) leave the pack completely inoperable...not really in a intermittently-failing state.