I am intending to use VictronConnect via Bluetooth for basic monitoring.
Questions:
If I create a VE.Smart Network that joins the smart shunt and the Orion, will this optimize charging while running the charging circuit off the alternator?
If I use VE.Smart networking can I still use VE.Connect via bluetooth for monitoring and retrieving battery SOC from the smart shunt?
I will use the “Charge Disconnect” output from the BMS to the Orion to manage the alternator side charging circuit, namely to cut charging in the event of cell issues. Can I assume that the Multiplus charging will be both optimized and protected by the BMS which is getting cell info directly from the batteries and communicating with the MultiPlus via VE.Direct? Importantly, that any cell issues will cause the BMS to send “Charge Disconnect” to the Multiplus via VE.Direct?
When the MultiPlus is not connected to shore power and the batteries are being used for AC, can I safely assume there is no back feed to the shore power outlet? aka there is effectively an automatic “transfer switch” inside the Multiplus ?
Is there anything I have have got wrong in my proposed layout or indeed anything I should add,. And finally, is there anything I especially need to watch out for beyond cabling/fusing etc? I realize I need to configure the MultiPlus and have purchased a USB VE.Direct converter for this purpose.
Yes, by sharing the actual battery voltage to compensate for voltage drop.
Yes.
Yes and No. The VE Bus BMS does not look after any charging, the charging settings are set in each charging device and each charger works independently. The VE Bus BMS is only a protection device stopping charging on over voltage or low temperature and stopping discharge on under voltage etc. It communicates via VE Bus, not VE Direct. Yes it will shut down the inverter or charger functions of the Multiplus if required.
When there is no shorepower, the input relay inside the Multiplus open, disconnecting the shorepower connection. See the block diagram, this is the relay on the left.
How are you going to stop your DC loads from discharging on low battery voltage, you should look at a Victron Battery Protect with the remote control from the BMS ATD port. As described above, the Multiplus is a VE Bus device, not VE Direct, you need a USB,-Mk3 interface. Adding a GX monitoring device would improve interconnectivity and monitoring, but is not essential.
Thank you SO much for your answers and suggestions.
Regarding question 3:
Per your comment “The VE Bus BMS is only a protection device stopping charging on over voltage or low temperature and stopping discharge on under voltage etc.” - Understood
Does the BMS also use voltage information it has received from the batteries via the BMS cables, and send it via VE.Bus to the Multiplus so it can then optimize its charging function?
I have considered using a Battery Protect, but space is limited and it feels like I’m performing key hole surgery making things fit! I’ll see if there’s enough space as I implement the build.
Wrt your comment VE Bus vs VE direct, can I assume that VE.bus is a true multi-access bus with any to any connectivity, and VE direct implements the same protocols but is point to point? aka two device interconnection only?
Does the BMS also use voltage information it has received from the batteries via the BMS cables, and send it via VE.Bus to the Multiplus so it can then optimize its charging function?
No it does not. In fact the BMS does not necessarily know the battery voltages, temperatures etc. As far as I know, the batteries decide if the voltage is high / low, too hot / too cold and just send an ATC / ATD signal to the BMS.
In terms of the battery protect, do not forget that the Victron Smart Lithium batteries do not have any isolation or shutdown inside the battery and the VE Bus BMS does not have any isolation either. If you get to a low cell voltage or low battery voltage AND DO NOT disconnect your loads, you will drain the batteries completely and kill them. ALL charging sources and all loads need to have some method of isolating them if the batteries require this.
You need to read up on Victron communication but I am not sure where to point you. VE Bus is the system that Victron use to communicate with many of their inverters. It is proprietary and is only for things like the Multiplus and its communication with GX devices, VE Bus BMS and a few other VE Bus devices. It does allow several devices onto the one backbone. VE Direct is for communication between a device, such as a solar controller, a SmartShunt or other device with a central GX device. It does not allow direct device to device communication from say a SmartShunt to a solar controller. Info can get to the solar controller from a SmartShunt but it has to go via a GX device not direct.
Now I’m confused… The VE.Bus BMS V2 has an LED indicator that shows “Temp or Cell >4V” which seems to indicate that the communications between battery and BMS is richer than simply ATC / ATD?
