I do have the issue, as soon as I start connecting both MPPTS via VE.CAN to the cerbo, my older Bluesolar 150/70 charger stops charging, although the Charge status becomes equal to the newer SmartSolar 250/85. (jumping from bulk/ absorbtion/ float statusses is not the problem).
It seems like, as soon both mppts are connected to the cerbo, the older bluesolar seems to get a signal that it may not produce any power or something, as the power output drops to zero, even if it was producing 500-1000Watt before I connected it. Meaning in stand alone function is works proper, but this way I can not monitor remotely both mppt´s at the same time.
I dont have a long enough VE.direkt cable, which I am curious of, if this would be a work around of connecting the one mppt via VE.Direkt and the other one via VE.CAN.
I am aware, that the older MPPT, is not capable of dealing with all new charge features, like DVCC among potentially others, But I assume that connecting via VE.CAN regarding master- slave Charge function as wel as for monitoring purpose, this shouldnt be any problem.
Should I maybe update, or better downgrade one of the Firmware? Cerbo, or one or both MPPT´S?
Interesting. I have a swt up with old and new mixed and dont have the issue.
(On ve direct for the old one and ve can for the new ones.)
I did update all the firmware at the time to the latest firmware, including the older unit. (Which i did at the time with a ve direct to bluetooth adaptor)
In addition to making sure the FWs are up to date, do you have the VE.Can chain terminated properly at each end? I know improper daisychaining/termination can lead to odd behavior sometimes, so would be worth a double-check.
hi, thanks for sharing both your experiences. All firmware are up to date, except for the multiplus 2, But I was thinking this wouldn´t have any to do with my issue. but maybe I should anyhow update it, just to make sure.
the VE.CAN is terminated on both ends… but also without termination, it resultet in the same situation.
I will also verify if all my cables are correct, by using the RJ-45 cable tester and evtl. swap it. just to make sure.
My solar charger where both running in stand alone mode last month (thus just 1 connected to the cerbo for monitoring reasons), now yesterday and today I connected them again with each other, and by doing so, the Charge Voltage of (I think) both MPPTs, suddenly rises to 48.0 Volt instead of keeping my battery at 47.4V for both for absorption and float; (it is a 12S Lion NMC battery, 47,4V/12Cells = 3,95V per cell), which it was doing in stand-alone mode working fine and just 1 connected via VE.CAN to the cerbo.
I dont know if this 48.0 Voltage limit has something to do with the CVL voltage of my BMS (which is set to 48.0V), but this limit may not be used at all, as DVCC, is fully dis-abled in the Cerbo. I don´t know if this voltage offset of +0,6V could come from another setting which I overlook? It only happens in master/ slave mode, and both running without VE-CAN doesn´t give this behaviour…
yes, it is indeed the old rectangular MPPT with Aluminium case and the display, as you mentioned.
Does someone know some clearer writings, about what is possible and what not, when ´mixing´ both old and new on the same VE.CAN line? For me it is clear, that the old MPPT can not be ´CONTROLLED´ by the cerbo, like ´DVCC´ would do (as this is repetitive written in different documents. And for this reason, DVCC is disabled in my setup)… But on the other hand, Why would it not be possible to link both via the VE.CAN line, just for monitoring and proper charging with the settings of the MPPTs itself (stand-alone mode, but with synced charge-status due to master-Slave) ? → As you wrote, I could imagine it has something to do with changes in the CAN-Protocol, but I did NOT find any document (yet) stating, both types MPPT should not be mixed in the same VE.CAN line, not even for monitoring reasons, as it seems not to work properly…
PS. just coming up in my mind. Is is true, that if in a master-slave configuration, all connected mppts, will be in the same synced charge-status. And if DVCC stays disabled, will normally the charge voltage settings be used of the programmed settings of the MASTER MPPT, instead of each individual programmed mppt? (is this true?) If this would be the case, and if the VE.CAN protocoll has been modified over the years, this could maybe be the reason of mixing old and new VE.CAN MPPTs does not work properly. Although the synced charge statuses works well and monitoring as such… but just one of the chargers ends up doing nothing and at the same time the charge voltage limit increases (in my case by + 0,6V)…
As a work around for now, I will try connecting one of the MPPTs to the BMS.CAN channel. If still not working, I will connect the newer MPPT via VE.Direct, as suggested, which might solve the problem, but I am not really happy with this ;(
There have been many changes to the CAN for all the integrations that have happened over time.
There are different speeds and different information shared along it and different method of sharing.
The older unit definitely doesn’t fit into the new ways and clearly stated by the fact that it can’t be controlled by the system at all.
yes, by time I do better understand and I do agree with you. It is not really intended to work well together, due to the old MPPT.
Just to share: I had a closer look on the connection status seen on the remote console and that looks as following.
The system recognizes both MPPT connections via VE.CAN (daisy chain connected at the time of writing)
the charge statuses are synced (seen by the display of the old MPPT and easy to observe by the leds of the newer MPPT)
BUT, reading the statusses seen by the CERBO, there seems not to be a ´real´ master- slave situation, as the newer MPPT says ´stand-alone´ and the older MPPT says nothing about any connection status…
→ For me the conclusion as well, that they are not fully communicating with each other, just half, which seems not to work as I expected it would.
So with the older mppts we used to have the charged voltage 0.2/4v above the ve bus charged voltage to force it “ESS”.
I am thinking since the CV rise to 48v may be the reason for the no production.
As it is voltage based production and triggered by that maybe its set point was under the 48v and so it saw its job as done?
just to finish this Topic. here my final findings:
If both different type MPPT´s are connected via VE.CAN, one MPPT (I think, depending on the connection sequence, but not fully sure), stops charging, although the charge status (bulk/ absorbtion/ Float) is always equal/ synchronized as the other MPPT (thus they realize that they should work together).
After just connecting both MPPTs, the charging MPPT, suddenly start charging with + 0,6V over the set stand-alone charge voltage. It looked liked, once the battery fully charged and beginning of the next charge cycle, it doesn´t have this overshoot anymore, but still only one MPPT is actively charging the Battery, remaining the other doing nothing. A little weird.
I also found that the Charge-voltage Overshoot was not BMS - CVL value related, just to Confirm to you (as I changed my CVL setting in my BMS higher as well as lower, and this did not change anything in the MPPT charge voltage, while overshooting). Ofcoarse DVCC is DISABLED at all time in this setup!
EDIT 29-01-2025:
I resolved this whole problem, - as suggested by some- by connection the old Blue Solar via VE.CAN and the other SmartSolar via VE.Direct. It working almost how it ideally should. Both chargers are charging with the correct set Stand-alone Charge voltage, without overshooting etc. At the moment of writing, they are both in Float status, and it looks like synchronized charging is active as well → EDIT: NO, Unfortunately I just discovered this morning, that both MPPTs are not working in a synced charge algorithm. In my case it is not a big deal, as absorption and float voltages are the same, but maybe this might affect some charge priority of one charger over the other (this kind of ´linked´ symbol is now continuously shown at the display of the Old rectangular BlueSolar MPPT, instead of blinking every three seconds as before, when both MPPTs where connected via VE.CAN. Assuming this actual status means it is connected to the Cerbo, bot not working in a synchronized parallel operation).
I still have the wish, to find better documentation and/ or clearer attention notes, that the old Rectangular BlueSolar MPPT 150/70 Series, should not be connected to any other type VE.CAN MPPT and most likely also not for other VE.CAN supperted products, as this seems NOT to work properly.
Up to know, I only found a similar comment with respect NOT to use the old Rectangar VE.CAN MPPT in combination with DVCC, but nothing about the fact, this MPPT is to be avoided to mix with the newer MPPTS/ hardware.
i was just thinking about that and came to add to the previous comment.
