Are you sure they aren't talking to each other?
See the answer at:
community.victronenergy.com
Well, I am not sure
. However, if they were I would have expected the numbers to have been the same, not just close?
I am surprised how close they are still, so it doesn't quite make sense and was really just an observation.
Ref the question posted on the Victron Community, one of the problems on the community is that often the replies are either incorrect or don't stand the test of time. In the case of the above one, that feature to sync data between BMV and Multiplus monitors and the displayed screenshot is no longer present as shown in the reply and was reportedly removed a while back.
Can't see much value in that syncing really anyway, as if you are syncing data to the MP monitor, you may as well just ignore the MP monitor if all it is doing is parroting the BMV? I only turned on the MP Monitor again last summer, just out of curiosity to see how far out it was and that is when I noticed it was oddly giving a pretty decent fist of showing the right SOC value.
I just thought it was interesting. Maybe others with a Multiplus, a BMV and a VRM setup could compare their own numbers?
Update:
Interestingly, I just reset the BMV SOC and the MP SOC followed the reset, so it is linked to it despite the values being different. I then changed to a different SOC and the MP SOC followed the change.
I wonder if the act of manually changing the SOC triggers the MP SOC to follow suit and then it will do its own calcs until the next manual change? Well, it does not seem to be as independant as I had thought and so likely not as accurate (which makes more sense). So back to my comment above really, I don't know if it has any value if all it does is pretty well copy the BMV.