Hi, I have two systems running. One in my camper with a Multi Compact on 12V LiFePo4 cells, the other with an 8KvA Quattro on 48V LiFePo4 cells. Both use the 2 signal BMS but also have the data link from the 123 Smart BMS.
The Quattro has begun performing strangely. It will favour grid over battery, despite the battery being fully charged. It is set to ignore AC with the general flag and Ignore AC assistants that have been working fine, up until they stopped. I’ve tried a Node Red control to see if that would help. No change, but had the output continually switch on and off with minimal load when the charging cycle switched on so have inhibited the Node Red for now. Brought the DVCC back to only read from the Quattro and it still only uses the grid. If the internal switch is set to inverter only, it’ll happily supply the loads until the battery runs out, but not when set to ‘On’. This persisted for several weeks then out of the blue the Multi compact in the camper did the same thing. This is wired from the Cerbo to inhibit the grid via a custom solid state relay. So this suggests that, at least for the Multi Compact, that the Cerbo is responsible. Re-booted the Cerbo in the camper and all is now well. The house is a different matter.
Hi @lxonline and thank you for your reply. My bad, I need to clarify.
The Multi Compact is linked to the Cerbo and uses the generator start feature on the Cerbo switched via the Cerbo relay and a bit of wiring. This is now behaving itself after a reboot.
The Node Red didn’t help so I went back to just using the assistants so ignore the node Red bit for now as I’m back to purely using the assistants. However I was using the Node Red Quattro internal switch function to go between charger only and inverter only which was an example I found on the net.
To my knowledge, no firmware update coincided with the initial failure to ignore AC on the Quattro (my main concern for this topic). It was happily charging when low and connecting when overloaded until it flatlined at 100%. All other Cerbo functions seem to be fine. All other Quattro functions seem fine, though there’s little to test aside from seeing the allow to charge and allow to discharge inputs are working.
Thanks again @lxonline, I had the same thought so disabled shared current sense on DVCC (but kept DVCC enabled with temp and voltage), switched to ‘no BMS’, cycled the Quattro off for ten seconds then back on again but had no change in the response except for the MPPT showing no BMS alarm. Re-established the 123Smart BMS and shared current sense.
Have I missed anything/what might you suggest to fully revert to internal stand-alone control so I can trace the fault to the Quattro if it persists?
To conclude this thread, I don’t have a definitive answer as to why, for no apparent reason, both inverters switched behaviour at different times without me altering any settings or (as far as I can recall) changing any firmware.
By way of resolution I have now checked and double checked settings (nothing was way out), disabled DVCC, re-checked settings both on the inverters and the associated MPPTs and enabled Solar and Wind Priority within the Quattro and Multiplus setting using remote VE Configure. I am now fine tuning the sustain setpoint offered in this feature under the ‘Advanced’ tab. I’ve also removed the Ignore AC depending on battery SoC or voltage for the time being as it would appear to not be necessary with the sustain voltage effectively being a low battery limit.
Further update on the Quattro, the above was not a solution and I was advised to remove all assistants as I variously had the Quattro stop charging and stop inverting at one point with SoC around 60% so neither low nor high.
With DVCC off and all assistants remove (pretty concerning running without BMS two wire link) the system charged up and discharged when power was removed. So wired the generator start stop to the temp input and added an assistant to trigger ignore AC 2 in plus two signal BMS and all was well. Then created a Node Red flow to switch the Relay 2 on the Cerbo based on SoC and load and although this may need refining, all seems well so far, no shut downs.
