Any suggestions for available/recommended relays/integrations between these components? My understanding is that 123 smartbms has a relay connection that should be able to talk to the multiplus....but I'm not yet certain of the specifics.
asked
Integrating 123\SmartBMS with Victron components like the Multiplus and Smartsolar mppt?
I think the manufacturer who has a test bed with Victron equipment may be best placed to answer on specifics unless someone here already has such a configuration in place. I do notice they offer an extended module you likely refer to, with CAN bus, which I suspect like with any smart battery (with integrated BMS) will then allow it to connect a Multiplus and control the charging etc. The DVCC has to be enabled.
BMS' with two contacts, "Charge Allowed" and "Discharge Allowed" can be used.
You need to run "Assistant" firmware on the MultiPlus and use the "Two Signal BMS Support" Assistant. This assistant is part of the ESS Assistant too.
I have a bespoke BMS and I use the two signals via opto couplers into the MultiPlus' Aux and Temp inputs. Dry relay contacts could also be used.
We are using and selling these 123smart BMS units and am very impressed with them
We have used them on the Multiplus Quattro and Multiplus II units
As WKirby states we have also used them that way
we have also used the victron VE-BMS as well, this is nice to use as it does not require the use on the AUX1 or AUX 2 or the temp inputs on the multiplus, as this uses the VE BUS network, (down side using the VE-BMS is that you then cant turn the units ON or OFF or adjust the Current limit on the CCGX or VENUS units)
the Load and charge relay disconnects on these units are a NC or NO relay so you have your choice
one nice feature in my opinion is
if it disconnects due to H/V then it delays recollection until a user nominated SOC level ie 80% thus the batteries are discharged down to 80% before charging is reapplied.
and another nice thing is its also a secound level of charge control
the same but in reverse applies for the L/V disconnect
also there cell balancing can be be at 3.4 , 3.5, 3.6 etc trigger points
the only thing thats question is there temp display as if the cel balancing is happening then it measures the balancing resistors temp, but when no balancing is occurring, it does correctly report the cell temp.
If I were to purchase the expansion module with the CAN interface, does this afford me more flexibility than using the two relays built-into the base bms unit?
I was think of purchasing the expansion module anyway for the purpose of adding an EV charging interface to enable charging my battery bank at level 2 EV charging stations.
Do note that the for the easiest setup where the 123BMS 'controls' the load and charge you actually need at least 1 aux input in addition to the temp sense and ideally you need 2 aux inputs on the Multiplus.
(My Multiplus, Compact 12/1600-70 does not have that for instance so whilst I use the temp sense on the Multiplus to connect to the 'allow charge' relay of the BMS, the relay output for the 'allow load' on the BMS is connected to a BatteryProtect to switch off the DC loads when voltage becomes too low via the remote control cable in the BatteryProtect.
The Multiplus can be configured for low voltage shutdown via VE.Configure on it's own.
I also tried running this with the 123BMS in so-called 'critical' mode but that gave more trouble actually as the SOC reported by the 123BMS became completely unriable.
