Hi!
I have a Multiplus II + Weco 5K3-xp battery + Cerbo Gx
I want to power non critical loads connected to ACOUT2 only when the battery SoC is superior to a certain threshold.
I tested the assistant from VE configure 3. But it’s using an internal battery monitor instead of the battery BMS SoC which result in inaccurate SoC.
Is there a way to control relay 2 based on the BMS SoC?
You can, with Node Red, send an Input signal from one of the relays on the Cerbo. That is, if you can get the SOC of the battery in Node Red. It does not look like the Weco 5K3-xp has a relay you could use.
I only use the internal battery monitor. I don’t use a battery BMS or shunt; I found them very inaccurate. When you get the internal monitor dialled in and do an actual capacity test of the battery, it’s very good at estimating the SOC. You really do need to just pick one. You could also look at the DC voltage, which is really the best estimate that you are near the top of the charge cycle.
Let us know how you go. If you need any Node Red help, just ask.
Hello Owen,
I’m also interested by this issue. My understanding of multiplus internal monitor was that it did not measured the power given by the solar pannel but only the charge and discharge current furnished or used by the multiplus. Therefore it can not be accurate? Am I wrong ?
Then how to use node red to send the BMS SOC value to the multiplus ?
I could be wrong but I seem to recall that despite the phrasing of the assistant, which SOC figure is actually used by the inverter depends on what you have selected in the GX device as the battery monitor. Despite the rather misleading assistant wording, the inverter syncs with that SOC figure if available. I don’t know for sure if your batteries’ BMS can be selected as the battery monitor in the GX device . But you can check.
