Standby Current MP2-3000GX

DIY
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i already have another Thread in the german section - but maybe someone could help me here?

I installed a really small setup for a friend, consisting of

  • 1 MP2-3000 GX
  • 1 Pylontech US4500 4.5kWh Battery

(the naterial was left over from another project, so why not give it a try…)

we wonder: the battery reaches the selected min SOC of 15% at like 9pm - not much sun during the day

Now, the MP2-System is constantly drawing about 20W the whole night

  • where are these 20W going?
  • why doesnt the MP2 GX hold the battery at 15%?

If we switch the MP2 off - Battery Consumption goes to 0

Would it make sense to have a NodeRED Rule to switch of the MP2 when min SOC is reached?

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The Multiplus is consuming about 11W in standby and the GX is consuming up to 5W continously. This is about 16W, the rest might be some other gear or just tolerances in the measurement.

Do you have a Smartshunt or do you “trust” the BMS?

The 15% will be held, as far as I remember, within a hysteresis. But I did not find any value for that… Did you check or observe if the battery is recharged when the SoC is dropped to e.g. 12%?

3

this is the SOC at night - min setting is 15%, it goes down to 11%

I don´t use a smartshunt, as there is only one single Pylontech US5000 connected

Would it make sense / did anybody try to switch of the MP2 at night with a NodeRED Script?

If i switch it off in the shown setting, Battery Watt goes to 0

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4

It seems that it doesn’t go lower than 11% - seen from the graph.
So, in a way, it stops discharging at set 15% - also seen from the graph - and then slowly goes to 11% and stays there.

You should take into consideration that the DVCC logic works in 5% steps.
It indeed stops at 15%, but the consumption of Cerbo and MP2 makes it go lower during time.
If it were to hit 10%, you will probably see a slow charge back to 15%.

5

what are these 11W in the MP2 used for?

If the MP2 uses 11W in 12 hours at night (winter) - 132Wh - not that much, but it´s 3 Percent of the battery capacity

As said, the project was for a friend, the MP2 and the battery was already there from another project

But i´m sure soon he will ask - i have 20 Watt at night - that´s over 5% of the battery capacity - for nothing

What do you think about switching at least the MP2 off automatially through a NodeRED Rule when minSOC is reached?

6

Electronics inside…
Even if you power off the inverter from nodered, the Cerbo must be running to execute nodered scripts.
And Cerbo is still consuming power from battery.

7

i understand the Cerbo needs some power to survive - but not 20W

i switched to “charge only” - resuit:

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looks much better for the client…

Maybe someone likes to check if this is only a bug of the beta release?

8

It’s not a bug. It’s physics. If you want electronics to be available instantly then it will idle power. The larger the inverter/charger, the higher that idle power will be.

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sorry, but this is not physics, it is definitely a bug - either only in the beta release or it was since ever like this

why should the MP2 always drain about 15W although he can´t do anything because the battery is empty?

You see - i switched from “on” to “only charger” - no more standby current

Yes, i agree there still is standby current for the GX - but at least not shown

If i´d give such a system to my very critical regarding energy waste, almost 80 years old, father - he´d say there must be something completely wrong

1 Like
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It was like that since forever…

When in ON mode, the inverter is working, even if there is no load connected to its output.
The inverter working means the electronics consume energy. About 15W. Which for an 2.5kW inverter is acceptable. (0.6% idle power).
And the sense of current is from battery to the inverter electronics, so there is loss for the battery.

In charger mode, it’s obvious that the sense of current is from charger to battery, so for the battery there is no loss.

Enable AES in the inverter and set AES mode to “Search mode” for conserving more power.

Come on…
It’s like in the movies… Keep the engine running during the bank robbery for when they exit in a hurry. For sure they don’t call a cab.

LE:
Now you’ll be saying…
If in charger mode and battery current is 0, why from grid is drawing 564W when only 559W is consumed…
Where is the difference???
Just kidding… No offense. :slight_smile:

11

haha, got you, but there is no planned robbery during night, so no need to keep the engine running :slight_smile:

what is AES Mode? sorry, my system is set to German language - could you send some screenshots?

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You can turn off the MP using node red (and also turn it on again). That’s how I keep the standby of my MP5000 under control. You will have to figure out on what criteria to base this of course.

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AES isn’t active as long as you have the grid at the AC IN.

@kr0815 The MultiPlus always need power to generate AC to follow the AC input and to be ready to take over in case the grid fails.

The MultiPlus only shuts down if the configured DC low voltage cut-off is reached.

Your system only reached the “soft” SOC limit wich means it stops to supply power to the loads but is still running.

That’s completely normal behavior, not a bug.

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Thanks for clarifying that with AES… :+1:
Stupid me to think about it when grid connected as you can’t have modified sine at output with grid input as long as it directly transfers the input to the output…
Well… if it had been a double conversion device, then it would have been different…

16

yes, i will do that

i see 2 easy criteria:

  • min SOC reached - MP2 off
  • PV power over 200W - MP2 on

of course some hysteresis is needed, maybe also using sunrise/sunset

In this small installation, it´s absolutely clear that when the battery is empty at night , it won´t be charged till PV is working the next day again