I have a Multiplus 24/3000/70 on my boat, originally installed together with a SmartShunt 500A and a battery temperature sensor on the domestic battery bank (lead acid), connected to the “T-sense” input on the Multiplus.
The auxiliary input of the SmartShunt is instead used for fetching the engines bank voltage.
Recently, I added a Cerbo GX (Mk2, if that matters), connecting it to the Multiplus with the RJ45 cable and to the SmartShunt with the VE cable.
All well and good, everything is working nicely, and I can also access the system via VRM.
The only bit that I am missing is the domestic batteries temperature.
I was expecting it to be available on the Cerbo GX remote console, “through” the Multiplus connection, also because I see everything else (V and A for both DC and AC, status, % of charge…), but the battery temperature is nowhere to be seen.
Now, as I understand, the battery temp sensor currently connected directly to the Multiplus could be connected to the Cerbo GX instead. Which brings me to the actual questions/doubts:
If I disconnect the temp sensor from the Multiplus and connect it to the Cerbo GX, would the temperature be visible via VRM, or not?
If I change the temp sensor connection in this way, would the Multiplus still “see” the batteries temperature and adjust the recharge accordingly, or not?
My reasoning is that I’d like the batteries temperature to be visible, but I think it’s more important that the Multiplus read it for its own management…
Anyhow, feel free to add any other suggestions/comments on whatever I may be missing.
Many thanks in advance!
I suggest that you read the DVCC chapter in the Verbo manual.
You need to enable DVCC, then SCS,SVS and STS. All items defined and described on the manual. STS allows a temperature sensor to be set system wide as the battery temperature. Hopefully you will be able to choose the temperature from the multiplus.
If you can not choose the Multiplus temperature sender then move it to the Cerbo and share it from there.
I had a new system so.put the temp sensor on the Cerbo. Activated DVCC and the shared readings from the battery monitor and everything worked perfect.
Many thanks for your prompt reply.
Must admit that I wasn’t even aware of this DVCC functionality, but It looks like it wouldn’t work with my system,.
In fact, according to the webpage in your link, DVCC requires a minimum firmware version of 422 for the Multi/Quattro, and my Multiplus is an old version (product ID 0x1910), whose latest available firmware is the v209 (which I have installed).
And i assume that also your suggestion to move the temp sensor to the Cerbo requires DVCC, right?
If so, that isn’t a feasible alternative…
Here’s a somewhat rough thought that just popped to my mind:
What if I connect in parallel a pair of wires to those coming from the temp sensor and currently connected directly to the Multi, and connect them ALSO to the Cerbo?
If both the Multi and the Cerbo could read the temp from the same sensor, I suppose I could kill two birds with one stone:
letting the Multi do its adaptation to charge current, and the Cerbo to make the temp visible on VRM…
Or would such parallel connection distort the temp reading (or worse, damage the sensor)?
Other than that, I guess I should leave the sensor connected to the Multi, get another one, and connect it to the Cerbo…?
Thanks, but don’t do what?
Connect the existing temp sensor to the Multi and the Cerbo in parallel, or get a second sensor for the Cerbo?
I struggle to see how the latter could be a problem, so I guess you’re referring to the former.
But I’d be interested to understand why not, anyhow.
I can’t find anything against that in the manual - though admittedly I can’t find a confirmation that it’s feasible, either!
Ok, as I guessed then.
But do you mean that the parallel connection would wreck the sensor, or that the reading would be wrong?
I’d rather not damage the sensor (obviously), let alone the Multi or the Cerbo, but if there’s no such risk, I wouldn’t mind wasting 10 mins to give it a try, and then cross-check with an IR gun the consistency of the temp reading…
The temperature would be wrong and you would risk damaging something. The temperature port is a live voltage source so you would be connecting live voltage sources and ground wires between the Cerbo and the Multiplus, no one knows what the result would be.
Well, I didn’t even try to turn on DVCC, after reading the firmware requirement that I mentioned in my previous reply to you above.
BTW, if anyone is aware of a workaround (other than replacing the Multi with a more modern unit, which I guess is the workaround Victron would suggest! ) that could allow me to enable and use DVCC, I’m all ears.
Based on what I read, it sounds like an interesting, clever functionality!
DVCC is important for coordinating multiple charge sources and sharing common sensor data which helps make charging safer and more efficient, ultimately better for your batteries.
It does support a range of older devices, but not as old as yours.
And for that there is only one solution.
I see, but it’s hard to justify the replacement a perfectly working Multiplus (even if oldish) just for sake of enabling DVCC.
Also because at the end of the day the only result I would get is sharing a temp sensor, since my setup is very simple, with the Multiplus charging domestic and engines battery banks (taking AC either from shore power or genset), or working as an inverter whenever at anchor I only need a little AC for the coffee machine or whatever, which doesn’t justify turning the genset on.
And my current Multiplus can handle all that just fine.
So, I don’t even know if/what other useful functionalities I’m missing - if any!
Agree.
You can run nodered on your cerbo.
The next release (currently in beta) will allow any sensor (could be a ruuvi etc) to be configured as a virtual temperature sensor which appears on VRM.
In my use case I am pulling temp information from a smart device, over wifi and then using vrm to report and chart the data.
I also have a couple of other temp sensors onboard, one for monitoring the saloon and the other for the freezer, which I can access with their own app (Govee).
But I consider them as a somewhat different topic vs. the electrical system, so I didn’t even consider integrating them in the Cerbo - as opposed to the temp of the battery bank, which BTW is inside the engine room and therefore exposed to highish temp excursions.
When you say that the next firmware will extend the sensors configuration, it will still need DVCC to allow the Multiplus “see” a sensor connected to the Cerbo, I suppose?
If so, it’s not going to change a lot for me, unless I replace the Multiplus.
Which isn’t going to happen, till it works as nicely as it does!
Your multi will never “see” a sensor unless it is directly attached to it.
If visibility is all you want, then connecting sensors to the GX helps with local and remote monitoring.
Just to be clear and put this in context, this is true of the OP’s Multiplus because it is an old hardware version that can not be upgraded to use DVCC and therefore needs its own temperature sensor to know the temperature of the battery bank. But with more modern equipment the DVCC functionality allows all of the connected devices to “see” a single temperature sensor connected to the battery bank and use it to adjust their charging profile.
Hi folks, just a brief follow-up on the matter, also as a FYI to anyone else possibly interested.
After reading elsewhere of folks connecting the same type of sensor which is being discussed to two different devices in parallel, I thought to try doing the same with the Multiplus and the Cerbo.
Which I’m well aware is something you guys advised me against, but my fear of damaging a unit is lower than the curiosity to try a solution for which I still struggle to think of a reason why it shouldn’t work.
Anyway, long story short, it does work nicely.
By now, the parallel wiring has been up and running for some days, and the temperature reading that I can now get through the Cerbo and VRM is consistent with the temperature I can measure with my IR gun (within very reasonable tolerances).
The only thing I couldn’t check is whether the Multiplus reduces charging current upon high temperature reading from the sensor, because I’m not aware of any way to simulate/test that.
Thanks in advance to anyone able to point me to such feature, if it exists.
Other than that, I guess I could try to heat the sensor with a heat gun and see what happens.
) that could allow me to enable and use DVCC, I’m all ears.
