question

Paul Beskeen avatar image
Paul Beskeen asked

Maximum grid use limit setting for ESS charging - timeshifting

My system is used solely for timeshifting electricity, no PV. I want to ensure that during scheduled charging of the batteries, that AC loads on the grid do not exceed my grid connection fuse rating of 100A. During cheap rate I can have a very large load on the system - ESS battery charging, car charging, water heating, washer/dryers operating + normal household use such as heating. When loads are not close to the limit, I don't want the ESS system limiting its charging rate, when loads are approaching the limit I want the ESS to moderate its charging rate to ensure the 100A limit is not breached.

I have an ESS configured using 2x Multiplus II 48/5000/70-50 in parallel and a Pylontech stack with an ET112 energy meter. Most household loads are on AC1 In. I have the grid set point at zero to minimise feed-in during the day. My input current limit is set to 50 to ensure the feed cable rating to the Multiplus is not exceeded.

What I would like, but do not see a control for (ideally I'd really like to avoid complexity of having to employ external control with ESS mode 2/3 or node red et al), is a "grid limit while charging" parameter in the schedule charge settings.

I have looked through other previous questions and don't see and obvious straightforward way to achieve this. I'm a bit baffled why such a seemingly important feature for safety and reliable operation for timeshifting is not available as standard. Perhaps i'm missing something fundamental, or my understanding of some of the settings is wrong?

What can I do to set a maximum grid limit without compromising charging performance when safely under that limit?

Cheers, Paul.

Multiplus-IIESSEnergy Meter
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2 Answers
matt1309 avatar image
matt1309 answered ·

Hi @Paul Beskeen


Someone correct my if i'm wrong but i dont think this is a native feature.

As you mentioned it is very much doable in node-red with some timer (If it helps at all I was worried about using node red as i thought it would/could lead to instability in my system using features like that but it's been ideal since i wrapped my head around it).


I'm currently using it to start/stop a water heater remotely controlled via a smart switch when there's excess power. I know little to no JS if that's also a concern

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Paul Beskeen avatar image
Paul Beskeen answered ·

I was hoping to avoid complicating my configuration further and also, lets be frank, having to learn yet another system - just to satisfy this one requirement.

My main beef though is that this feature seems important from a safety and avoiding household system overload perspective. Many, if not most, EV chargers seem to have some form of current load management system these days. It may even be a legal requirement in some jurisdictions.

What is the right approach to lobby for new features in ESS?

Cheers, Paul.

3 comments
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Paul Beskeen avatar image Paul Beskeen commented ·

Perhaps @Guy Stewart (Victron Community Manager) could provide some guidance on that last aspect?

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matt1309 avatar image matt1309 commented ·

I've seen a few others request the same feature. You may be better off moving this from questions to modifications. As I've seen it in there before.

From safety pov I suppose you can limit overall current drawn by multiplus but I agree it would be a great feature to have it also factor in grid meter data.

I suppose its only an issue if you have loads in parallel with multiplus on AC In. Any other configuration ie loads on ac2 out or ac1 out youd be covered by using the mutiplus current limit.

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Paul Beskeen avatar image Paul Beskeen matt1309 commented ·

Hi Matt,

Yes, this is definitely specific to ESS systems with loads in parallel on AC in. I'll move this to Modifications and see if there is any feedback.

Cheers, Paul.

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