question

Hello,

The MultiPlus Compact has its own battery monitoring system to define the SOC (voltage method) and can therefore switch the inverter off and on again, depending on the SOC values defined in the VEConfig software.

If the MultiPlus is disconnected via a BMS, it can no longer charge even if shore power is connected.

In my installation I have a SmartShunt that calculates more precise SOC values. The SmartShunt and the MultiPlus are connected to each other via a CerboGX, so the MultiPlus uses these exact SOC values and switches the inverter off at 25% and on again at 30%.

Conclusion: The MultiPlus switches off the inverter itself and does not have to be disconnected via a BMS. Only the consumers should be separated via a BMS.

I hope I got your concern right and my explanation helps you further?

greetings

Hey Ulrich, many thanks for your answer. This has already belonged to me very much.
I also have in Smart Shut and a VenusGX. I think that I can build the same infrastructure as you.
For the 12V consumers I have a BP-220. This modul control directly via the BMS.
Now the question is, how do I control the loading of the Multimaster via BMS. There a many Way.I no longer need the cable mentioned above, because I only want to control the charging with the BMS

I use the temperature input, which is configured as aux input when set lithium-ion.I believe I need this cabel for direct atteched “Non-inverting remote on-off cable”. Improve: In this case, if the BMS is off / defective, no charging would buy either, since the control input responsible for charging is high. This is a very good security for a sailing boot.

Alternatively, I can connect the charging control cabel to the Venux GX, and then control the charging behavior via the VE.Bus.

Which way would you take?

I'm not sure if the temperature sensor is allowed to be misused like that. The cable represents an electrical connection. As long as there are no equalizing currents?

If the Venus GX has a potential-free input, then this way might be safer.

But:
If you have a SmartShunt, you have to set your battery type for it and it will take care of everything and tell the MultiPlus how to charge it.
Do you still have an MPPT solar charge controller? This can be connected to the SmartShunt via SmartNetwork. This also controls its charging behavior.
Right now my MPPT solar charge controller will be switched down because my batteries are full. (See: https://www.zoomsoft.de/grafana)

In my installation in the motorhome, I only separate the Orion-Tr smart DC / DC with a SmartBattery Protect, which is connected to the VE.Bus BMS. Because this is not connected to the SmartShunt.

I use the temperature input of the MultiPlus with the temperature sensor connected to the battery. My MultiPlus still has a VE.Bus SmartDongle. Now the MultiPlus sends the temperature of the battery to the SmartShunt and the MPPT solar charge controller.

Ok, that's all very different from what you actually thought. I hope it gives you a few ideas on how to best implement your installation for you.

greetings

Hey Ulrich,

yes it’s possibel to use the Temp Sensor as input. Yout found the paper here.

https://www.victronenergy.de/upload/documents/Manual-Connecting-other-lithium-battery-systems-to-Multis-and-Quattros-EN.pdf

i am not sure what is the right way to connect the input. I have only a 13V signal. Is a optocoupler the best choose to prevent equalizing ? I also connected the Shut and the Multiplus to my Venux GX. I see both in the menu but unfortunately, it is not clear to me at which point I can interrupt the inverter based on the shunt.

The Solution with grafana ist very nice!