question

• Some update:

As stated before the issue is that the charger does not turn off when the Active SOC limit is reached. Switching to "inverter only" is not a solution because the critical loads will be powered from the battery. I figured out the solution is to go to Passthrough mode.

All relevant controls are available in Node-RED. Injecting a "Disable Charge" to the ESS by hand is switching to the desired mode reducing the power consumption to an acceptable minimum. :-)

I'm somewhat wrestling with Node-RED as this is my first encounter with this kind of programming. Having knowledge in C++ and Python is not helping, it's totally frustrating. :-(

To the Victron ESS Team:

Why do I have to jump through hoops to stop my Multiplus from wasting power?

• I did not buy the Multiplus to learn Node-RED programming!
• The ESS-Assistant should go to Passthrough by default if no exzessive energy from solar or battery is available!

Hi Glenn,

Thanks for joining the community and replying to my question. I appreciate it!

I'm sure it's the system programming. For big multi-phase / multi kW(h) ESS it may make no sense switching to Passthrough because you probably never encounter a low battery state for a longer period of time. The Firmware seems to be the same for all Multiplus, so my case is not covered.

As a System-Design-Engineer I have to admin that overall function has a higher priority than tweaking the the last bit of efficiency. If it wasn't for the loud annoying hum, I would have never looked into the power numbers.

After the dust from frustration and anger has settled, I created a first Node-RED flow which turns off the humming when the battery is depleted for a good night sleep. As soon there is enough excess solar energy for charging it turns the charger back on.

Hi @tom w

I would question your use of ESS at all, considering your stated use case. Like swatting a fly with a sledgehammer. Unless you're exporting power to grid from your little 500VA, then ESS isn't necessary. Just adds complexity (as you've found), and what you want could be achieved far more easily with other methods.

Your system could be more stable, not leak power, nor groan at you. There's still a few little things that need attention to set up to your preferences, but if you're prepared to flick ESS we could help point you in the right direction.

Hi John

At the first glance an ESS with an 500VA inverter and a 1.5 kWh battery does not make much sense.

However,
that's not purpose of the system.

The main objective of my little ESS is providing an UPS for my Home-Assistant server and electric shutters. My server and the related network appliances require 50W around clock and each shutter draws 200W for less than a minute when in action. So having a 500VA UPS is a perfekt match with some headroom. I also want to add my refrigerator to the critical loads but this requires rewiring my kitchen.

To recharge the battery and cover my basic loads of 110W, I have 600W "Balkonsolar" system because it requires the least amount of legal paperwork here in Germany. 600W is more than enough to cover my basic consumption but it's not enough to power power my coffee maker. As result on sunny day I feeding 1-2 kWh back to the grid. This happened twice last week and reminded me that I forgot to unpack the Multiplus since I bought it 3 months ago.

Now we come to the second objective, Power-Assist. On a sunny day like last Wednesday I can brew my coffee after lunch for free because the Multiplus and the solar inverter combined are able to power my 1.1 kW coffee maker even in winter.

After the sun has set, the ESS can use the battery to power my home as long as it can. And when battery is depleted to the minimum allowed, I want the ESS to consume as little energy as possible.

So yes, from time to time I'm swatting flies with a sledgehammer. But I did not buy the hammer for swatting flies. I just happen to have a sledgehammer and if it is the next best tool for swatting an annoying fly, I use it.

Regards Thomas

@tom w

My point still stands, I see no reason to run ESS on a ups.

Lets try an example using your 600W, but rough figures. Set an ac input limit (ACIN) to the Multi of 2.6A (600W@230V), so you can't draw more than 600W. Power Assist adds to loads higher than that. All bog-standard stuff.

Using Assistants (not the ESS one) in the Multi you can switch off (Ignore ac) the ACIN whenever you choose, and have it switch back on under certain conditions, like low SOC or loads over 600W. Job done.

Access to the Multi settings is a bit clunky, so an improvement there might be to run a signal wire pair across from a GX (does RPi have a relay?) and use the Generator option in the GX (very powerful settings).

ESS is only one of a number of Assistants, and you can build a program from multiples of the others. ESS is designed to push'n'pull at the grid, and that's where your reported issues are coming from.

This is standard stuff for offgridders and casual grid users. No ESS (banned for gensets), and no NodeRed needed..

Hi @JohnC

Let's agree that we disagree!

Here in Germany we have a 3 phase system and I'm paying for the power balanced over all phases.

The example of limiting the input power only on the one phase connected to Multiplus does not compensate the total power consumption. Therefore an ESS compensating all 3 phases with single phase feed in is way to go in my case.

Adding more wires and making the hardware setup more complicated is not the right thing to do considering you have all the information and controls available in Node-RED for fixing the issue in software.

Admitted Node-RED has a very steep learning curve. I was thinking far too complicated and I was missing basic programming features. After realizing that I just have to think like a toddler when creating a Node-RED flow, I already came up with a basic flow that is capable of eliminating the power waste and humming over night.

I'm currently fine tuning the charger off condition, so that I don't turn off the charger too early, when clouds are blocking the sun during the day.

In the end I want my UPS paying for itself by making use of my excess solar power.

Please ignore my rant at beginning of this question!

If it haven't been for the annoying humming, I have would never look into the issue.

Now, I have some basic knowledge of Node-RED and I created a flow that works around the constant switching losses of my Multiplus.

Thanks for your patience!

please help me set Shelly EM as a grid meter, I see it in Device list but not in Energy meters

@Marian Titieni

My Shelly3EM only appears only Dashboard as well. Under "Settings>Energy Meter" I see nothing.

Neither can I see my Deye-Inverter's Shelly2.5 under "Settings>PV-Inverter" but I can see it in the dashboard:

The Shelly-scripts are injecting the required messages directly to the dbus and don't create a device that can be configured using the settings menu.

I'm using https://github.com/fabian-lauer/dbus-shelly-3em-smartmeter and https://github.com/Halmand01/dbus-shelly-1pm-pvinverter-mult-instance for my Shelly devices.