question

Hi @Fideri

Just to clarify, you want to monitor output of two quattro separately in parallel for a specific reason? Normally you wouldn't monitor them separately, they get aggregated into "one unit" when put in parallel. Which is what confused me

The more i think the more i get confused by it. I dont quite understand the aim. In theory if installed well/properly the two units are equally balanced. So to get per unit data you'd just divide by 2?

If you're doing this for a specific reason that resolves by confusion i think you'll likely have to flag the ET112's as AC load meters given this isn't really a common feature people use and it wouldnt show in VRM main dashboard as 2 separate units for this reason, you 'd have to view the data in the advanced tab.

If you're looking to compare the balance of the two units. I personally wouldnt use vrm for recording this data and i'd do it on something more DIY that's more fit for purpose (also cheaper). You could use ET112's but feel like there's cheaper alternatives if you go the DIY route and store the data in influxdb/grafana and built out purpose built funcitonality rather than "making it work on" vrm

@matt1309

You are right on everything.

The 2 Quattros will operate in parallel. The second one is still in the box. An installer will fix it (under my strict instructions because even Victron recommended techs know nothing where I live). I will use a multimeter for balance, if necessary.

But I'm a data junkie. I'm usually not on site, so physically measuring the respective outputs of the inverters is out of the question. I rely on VRM.

Simply dividing the global output is an interesting possibility, but not ideal. I understand that any multiple inverters are never perfectly balanced. The proposed approach would have the added advantage (this is not the main purpose) that I will see the data if the inverters, for some reason, are going out of balance. I understand even with meters, I wouldn't be able to see the output of the individual inverters on the main screen but elsewhere.

It's a bit of an overkill but I can't think of a cheaper way to get the data through VRM.

F.

Hi @Fideri

No worries I understand now. Benefit of victron is the system/code is so open you can get stuff to work even if its not natively supported.

I agree the et112s and all supported meters are pricey.

How familiar with python are you. Victron gives explanations on how to make custom drivers (installing custom devices). You can also do in c++ but python is easier

Here is the wiki.

https://github.com/victronenergy/venus/wiki/howto-add-a-driver-to-Venus

Here's a example script

https://github.com/victronenergy/velib_python/blob/master/dbusdummyservice.py

However the community is well ahead of that and have integrated loads of devices. The one that springs to mind is shelly power meters. They're likely not as accurate as et112 but imagine they'll be pretty damn close (and you can probably manually calibrate if you wanted to). Just search shelly pm victron github. And there'll be a selection of community made custom drivers for various shelly power monitoring devices.

In regards to vrm I'd still advise recording data seperately in influxdb with grafana as gui given the energy meters, device type aren't really meant for this type of monitoring but I belejeb e setting the meters as ac loads won't skew the critical data that's needed/use by the system.

If you're very familiar with python you could make a device you want if increased accuracy is needed. Maybe an arduino or esp32 device and just have a "dummy" energy meter setup using the scripts in the wiki above. And then send data from arduino to gx via mqtt. This is far more involved than copying people's shelly power management drivers but if you are into that kind of thing then would probably be fun.

An example of a community made shelly pm driver

https://github.com/fabian-lauer/dbus-shelly-3em-smartmeter

@matt1309

Very good ideas there. I particularly like the possibilities of Shelly meters or "virtual" meters. I know a bit about Python. I'm primarily a PHP/JavaScript person but I'm keen to learn as time is on my side.

Thanks.

F.