Thanks for the confirmation, Nodred installed, V3.1.15, came with the latest OS large. It didn’t have the DVCC max charge limit listed as an option only ESS max charge limit. But I found a post by “Owen” in a similar thread where he had a flow, pasting this flow seemed to maintain the DVCC link he had and it worked when I put my own logic around it. I monitored it at lower battery states of charge and used message block in the debug windo at first, when I was happy I uploaded it. It has automated the last 3 step changes and seems to work well Hold to within 10% nder normal operating conditions. The sun comming out suddenly causes issues, but I am creating a new script in HA to turn on the ducted AC at 85% SOC, so this will take the edge off that issue.
I still need to sort out the Modbus issue. Even with the latest OS installed on the CerboGX, the two fronius units are not showing in the “connected” devices list and the MPII is still frequency shifting to control them.
Thanks again for the pointers on Node red and the confirmation it wouldn’t be too much load for it. This is at least a very good start to fixing the issue. Now I just need to figure the Modbus issue.
Great stuff I’m glad you got it going! Now you can make your system do whatever you want. Let me know if you get it fully sorted and undisturbed by cloud spikes.
So now to get to the Fronius units,
how exactly are your units connected to each other and to your network and eventually the cerbo?
is everything on a local network?
Are the fronius units set to static or dynamic?
Can you send screenshots of all the setting pages on the fronius and on your cerbos modbus tcp server settings, services etc?
I have had the most success just connecting my cerbo with wifi (needs to have a strong signal) then setting up the fronius units to be on a static IP, wiring them to each other respecting the IN and OUT chain as that is very important, then wiring straight into the ethernet port of the cerbo and putting the cerbo on the same IP range as the Fronius units, then they have no chance of being lost.
I’m also in Australia (Hunter Valley NSW) and not too far different system.
I currently have one 48/15kva Multiplus 2 and one MPPT 450/200 which is charging my 2000 ah lead gel batteries on their last days.
They still accept the full 200 amps @ 58 volts so right up to the max output of the MPPT however I am currently assembling some LFP batteries (4 x DIY packs) so will as of Sunday be charging 48 kwh of LFP.
I am building up my system in the next couple months so want to avoid similar problems to what you are experiencing!!
I currently have 30kw of PV and am installing a further 20 kw next week going through a second MPPT 450/200 with all hardware ready to install.
For stage 2 of my expansion I have another two 48/15kva Multiplus 2 and will as the next step be converting my system to 3 phase.
For stage 3, I have two 15kva 3 phase Fronius which will be AC coupled to my system together with another 30 kw of PV.
The main purpose of this will be to heat a swimming pool remote (200 metres) from my power shed
The PV array feeding the Fronius will be located 300 metres away utilising full solar access on a clear hill where I used to have a windmill.
I plan to run the PV DC at 800v to the Fronius inverters at the pool.
Currently waiting for Yixang Energy in China to release their MB56 DIY battery cases so I can install more LFP capacity - hoping to get it up to 144kwh.
Stage 4 will be EV charging for both on road and off road vehicles.
What is the purpose of connecting the LFP to the Victron Cerbo?
I may be mistaken but the JK BMS will look after the LFP and your MPPT will look after itself?
Have you tried to disconnect the comms from your LFP to Cerbo?
Hi Daniel, Sound like a great system you are planning good work.
I think the most of my problems and potentially something for you not to loose site of when you add in your Fronius inverters is the Factor 1 rule. So I have 2 x 48/5000 installed, and I have two Fronius inverters, one is 500VA, and the other is 3000va. combined they deliver almost the full 8kw. The larger delivers 4800 - 4900 w under peak sun, cool weather conditions (current conditions) and the smaller around the 2700w. I am thinking the combined output of 7600w is potentially the cause, the two units in parallel should be able to take 8000w. I have been very careful to not oversize the AC cable (4mm) between the units and the MSB, and the two cables are Identical length (7m) battery cables the same to the Lynx distributor. I have another 500VA Fronius I was going to replace the 3000 with, and I also have another 48/5000 that I was using as a battery charger, but haven’t needed it it in the last two years. Maybe I should parallel up the third 48/5000 to make the Factor 1 rule very comfortably in the 12000w. It apears the two 48/5000 cant deal with the sudden surge in solar when the sun comes out from behind the clouds. They just dont rise quick enough. I have tried to configure Modbus but I don’t believe its working. That said I haven’t been home/ we haven’t had a full sunny day for the last 4 days so I haven’t seen the same large charge spikes.
I have the V1 of the very same battery cases, the Breakers they supplied where rubbish. I have new ones to replace them with but haven’t as yet (similar to V2) so the BMS is whats connected to the Cerbo, not the actual batteries. I also have a victron shunt. I figure all the big commercial systems all have the BMS talk directly to the controllers, so it would be better if my system was set this way. It doesn’t make any real difference anyway, its only reporting alarms and and the SOC, which drifts as much as 20%. Its not as I though slowing down the charge rate at all as the batteries get full. I got some changes when I go back through the trends, but this corresponds directly with a cell over voltage alarm, which is when the BMS stops charging that battery or limits it to 10amps until the BMS can sort out the cells. This has only started happening in the last month when I have added the additional 8kw of MPPT solar. I very rarely got 10 150amps charge previously. But now I am pushing 220 easy, and when the sun comes out from behind the clouds suddenly I have seen over 310 before the system can control it. I have 5 x 200amp BMS connected to EVE LF280K. In the settings I have the charge limit set to 57amps 0.2c I also have a Jakiper 5kw battery with a charge limit of 20amps, converted to a JK BMS. All six on the bus.
I was reading yesterday in the MPPT manual they will sync if I use a VE can bus connection and control as one. I have them connected with VE.direct cables to the Cerbo and thought this would do the same thing…. Anyone enlighten me on which is better. I have seen them throttled there output when the system is running normally.
As a short term fix, I have enabled the NodeRed on the cerbo and utilize the reduction of the charge current as the batteries get above 85%, it drops the charge rate by 25amps every 5%. This is probably better for the batteries, but doesnt get around the cloudy day issue and the surges in charge amps, so I have also enabled the Main ducted Ac on the house to come on as a base load of 4.5kw as the battery gets to 85% this should cap the max charge rate by taking out the largest Fronius inverter’s production. I need to do some load shedding flows for this based on Solar vs load / charge rate and then learn how to export this info to Home assistant. At the moment HA does all the AC control (4 of them) bringing them on as the battery SOC increases, but this alone is not really ideal.
I have been back over the docs and everything is correct, I swapped the little switch over on the Network card the other day and that has made no difference. Both units are connected via cat5 to a network switch, the onto the Cerbo GX, all are on there own network that does have Internet access for the Cerbo. There is nothing else on this network.
The cerbo sees the inverters, sees all the data from them, but they dont appear in the Modbus list.
Its got me stumped…anyone got any hints to try, it must be something simple as it is effecting both of them. I don’t have the fronius units connected to the Web server at all…maybe this is it ??
Thanks for the info, have you run through the setup on the app on both the fronius units? I believe you have to do that at least once to get them running, also just cherck that they have unique IDs to not conflict with each other, you set this on each inverter
To me the app makes it so you do not miss anything, but you should be able to do it all on the web, would you mind sharing screenshots of all your tabs?
You mentioned they both need a different address, is that the 101 offset ? apart from Ip I couldn’t see anywhere to set any address. The Cerbo shows them having a unit ID of 20 and 21 in the “Attached devices list”
Ok I have done a few things this morning, lost the 5kw inverter completely for a while, but its back now. Still no changes, the only devices listed in the modbus section are the 2 x EV’s
