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Magnus Pernemark avatar image
Magnus Pernemark asked

Allow Charge and Allow Discharge Multiplus-II - not working

What should this mean?1631813437458.png

My interpretation is Charging is allowed and discharge is not allowed.

What it really means in my ESS instalation.
"Discharge is not allowed, but charge at maximum current possible."

When "Allow to discharge" is set to NO, the "Low battery"-led starts to flash, and multiplus starts to charge with maximum charge power, it disregards state of charge, it ignores ESS set points... it just charges.

I use the 2-wire BMS assistant with ESS.
The allow to charge works as it should. When NO it stops charging, when set to YES it charges, if ESS grid point allows it.

I am on latest firmware on the multiplus-II and VenusOS is 2.80-ish (same behaviour on lower venusos as well)

Is this not a bug? Am I the only one?

Multiplus-IIESS
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3 Answers
wkirby avatar image
wkirby answered ·

I seem to vaguely remember having this problem.
For me it was the grid code setting interferring with the Two Signal BMS on Aux1
I have UK grid code (maybe you have similar) and I had to untick this box on the Grid Code settings as shown below:
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Magnus Pernemark avatar image Magnus Pernemark commented ·

Yes, I have heard about the "disable Feed-In"

It is turned off (unchecked). Have doubled checked at two different times. I have european grid code.

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tommas avatar image tommas Magnus Pernemark commented ·
After updating mine was set back with checked box.. with German grid code. I have it again unchecked and than it worked for me. Had same problem for a year ago or so.
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Magnus Pernemark avatar image
Magnus Pernemark answered ·

Just realized I already have asked this before.. but it is still a bug in this new firmware
https://community.victronenergy.com/questions/89813/multiplus-ii-48300035-disable-discharge-starts-cha.html


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wkirby avatar image
wkirby answered ·

I definately had this working in the past.
I'm sure I've got that MultiPlus lying around that I'll set this up again to test. It should work because it did work well for me for several years before I changed to a managed battery.

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wkirby avatar image wkirby ♦♦ commented ·
I did get a change to wire up that MultiPlus.

It has FW 478 on it and the 2 signal BMS works well.
Then I updated to FW 487, however the 2 signal BMS is still working just fine for me.
I test by manually disconnecting the BMS connectors from the BMS and it triggers the Allow to charge / Discharge to NO and then to YES upon re connection.

Unfortunately, I could not find any problems on my system.

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Magnus Pernemark avatar image Magnus Pernemark wkirby ♦♦ commented ·

That was bad news for me.

The Allow to charge works fine.
The allow to discharge does not. When the relay closes this, the "Low battery" LED turns on on the MultiPus-II and it starts to charge from grid.

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2-wire settings
It's this setting in the ESS
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And the AUX1 disable feed in is disabled
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There is an update to the ESS assistant. I will install it and check it out


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Magnus Pernemark avatar image Magnus Pernemark Magnus Pernemark commented ·

It did not help to upgrade the ESS assistant. Same behaviour.

I recorded a demo here

https://youtu.be/aqHtHZOcEh0

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wkirby avatar image wkirby ♦♦ Magnus Pernemark commented ·
It looks like it is responding to the inputs.

hat is the ESS mode? If you have keep batteries charged mode, then it will take full power from the grid whenever it is allowed to charge.


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Magnus Pernemark avatar image Magnus Pernemark wkirby ♦♦ commented ·

No I do not have keep batteries charged. I want to charge only when grid is below grid set point.


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