So, I did a little house-cleaning in preparation for more pylontech bateries - got a new rack and moved my 7th US5000c to it.
So far so good.
Problem started when I tried to restart the system - it failed due to me not plugging the BMS cable from cerbo to my pylontech A/CAN port. Or, to be more specific, I replaced the cable, thinking it’s basic ethernet cable - as the previous one was too short.
The cerbo started, but I was welcomed with immediate beeps and error “#67 - No BMS” from the MPPT.
I realized by mistake, removed the cable, took the old one and moved the battery up in the rack so the cable fits.
Restarting everything - still the same error after ~20 seconds.
But now here is the problem - this time, I can see the BMS can communicate, no errors, no Bus warnings.
Same goes for the MPPT, but it still reports the same error.
I tried to go to the Settings → Devices → MPPT 250/100 → Networked operation and there was a value for “BMS controlled”. I clicked on it, the value changed to “No” and the error disappeared.
However, now the value is read only and I cannot set it back to pylontech BMS control.
That should automatically revert once the MPPT sees the data from the Cerbo - i.e. once the cerbo has the bms data and DVCC is active. Having cleared that error, I would power down the whole system and try rebooting from scratch.
Sometimes a firmware mismatch between the Pylontech can cause a block on the bus.
Try selecting a different Pylontech as master. Normally you should use the newest as master.
For me that didnt work and i had to use one of the older as master.
Or to find out if the new battery is the problem, perhaps due to a firmware mismatch, you could first try to remove the new battery to see how the system behaves. You may want to update the firmware on all the modules, following the procedure prescribed by Pylontech.
So far I only have the batteries I had for a year, the only new piece is the rack. The new ones will arrive in ~10 days only
But if a restart tomorrow will help it - perfect
Will, for sure, try. And I do have different firmware versions in the batteries (my pylontech ESP32 monitor knows), but the current configuration is exactly the same as it was this morning.
But thanks a lot for the tips - I love this forum, always helpful.
Both of the work, both are visible. As said - the only thing that “went wrong” was that I’ve used temporary wrong cable for the BMS can. Replaced it back, everything communicates, but the problem is the MPPT ignores the BMS
OK, I solved the problem; I’ll document it here for others.
What I did is - I modified the CAN id - which I should not have done.
My reason - there is a Home Assistant Modbus TCP integration for victron which failed to load MPPT data if the ID was 0. But the problem was not the CAN id, but the VRM id. I instead of modification of the VRM id modified the CAN id - this made the MPPT still work, but stopped the MPPT control by BMS.
Changing it back to CAN id 0 and rebooting the system worked.
I cannot check if the HA integration works, still, as there is a different, unrelated bug, that forces me currently to disable the integration
