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micmak avatar image
micmak asked

ESS doesn't use Battery when PV is not available

Hello,

I have a Multiplus II setup with RS 450/150 and 3 BYD Premium LVS (total 12kwh). Everything is working fine if PV power is available:

  • If Load > PV, and SoC > minimum SoC, the battery will compensate the delta, grid remains unused

However, during the night, when PV is not available, the batteries are not used. With the same conditions as above and same configuration, only the grid is used when PV is gone.


The lights will flicker as well, as it sounds that the inverter is switching to batteries for a fraction of a second then back to grid.

DCL never changes, always at 192A.


I create the below custom graph to show the issue, minimum SoC is set at 20%

1703665519475.png

Multiplus II is running v498, GX and RS are lastest firmware.

here is the ve bus state:

1703668712309.png

I appreciate any insights or ideas. I am familiar with ESS settings, it's working fine in another setup I have, although a bit different (quattro/fronius instead of multiplus/RS).

Multiplus-IIESSBYDMulti RS
1703665519475.png (95.2 KiB)
1703668712309.png (25.9 KiB)
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Alexandra avatar image Alexandra ♦ commented ·

@micmak

Start by updating all the firmware on the system, including the inverters then go from there.

Do you have peak shaving on?

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micmak avatar image micmak Alexandra ♦ commented ·
it is set "above minimum soc only". I am a bit concerned about updating the Multiplus, as I read it needs to be reconfigured. Is it enough to download the config through VRM, update and then reload the confirm through VRM? no need to reload ESS or anything? I haven't done this before
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jeanmarie avatar image jeanmarie micmak commented ·

Remove the "above minimum soc only" it mess up the ESS and force it to go in passthru bypassing any setpoint in current or power limitation.


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micmak avatar image micmak jeanmarie commented ·

I added the ve bus state graph as well in the original post.


Regarding peak shaving, I saw this in the documentation:

The default setting when using the Optimised modes is 'Above minimum SOC only.' Use this option in systems that do not perform peak shaving.

Do you mean it should be "Always" instead of the default?

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jeanmarie avatar image jeanmarie micmak commented ·
I noticed on my installation several time where the multiplus switched to passthru mode which act as the following

- bypass all limitation for power and current on AC-IN

- force the charge of the battery despite it is not empty and far from min soc

Since I moved "peak shawing" to "always", I don't have this misbehavior anymore


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Alexandra avatar image Alexandra ♦ jeanmarie commented ·
The half half update with the firmware is likely part of the cause.

In future don't update anything unless all is updated. It is simply not worth it unless you need some new feature. And then should be done fully.

In theory reconfiguring over the VRM after a firmware update can be done. I never do it though. It is usually too complicated and requires physical shut down anyway of certain components like AC PV so you might as well be there.


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2 Answers
phoenix avatar image
phoenix answered ·

I'm running a MP II 3000/24, ESS, above minimum soc, latest FW. I had a sort of related issue 2 days ago. I had very little solar and put on a load of about 1kW. The MP did not inject. Checked it was in bulk. I left like this for about 30 mins, then decided to add another 2kW. At this point it decided to start injecting. I'm using a CT, and the readings matched those from another independent CT so I decided it wasn't a dodgy 3.5mm jack.

I must go back and look at the logs to see what state it thought it was in and try again one morning.

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micmak avatar image micmak commented ·
the only way for me to get the batteries involved is to set the input current limit lower than the load. otherwise, the behavior is consistent, and wrong...
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micmak avatar image
micmak answered ·

BELOW TO BE IGNORED, CONFUSED Multi RS with SmartSolar RS

I was looking at this issue again and found this in the documentation:
Please note that the ESS implementation for the VE.Can Multi RS is managed differently to that for the VE.Bus products.  No assistant is required to be installed, ESS settings are available out of the box.

It is not yet possible to adjust the available ESS settings via the ESS menu of the GX.  The ESS menu of the GX will display 'No ESS Assistant found'.

It is also not possible to change ESS settings via the controls menu of VRM.
It seems the installer is not aware of this and he installed ESS on the GX anyway. If I understand the documentation correctly, I should delete the ESS from GX and use VictronConnect to change this setting on the RS directly (or through remote VictronConnect).
Reference: https://www.victronenergy.com/media/pg/Multi_RS_Solar/en/installation.html#UUID-dbb3dd2d-4d98-5685-a28f-1d308f1705cb
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nickdb avatar image nickdb ♦♦ commented ·

The Multi RS Solar and the Smartsolar RS charger (450/200 and 450/100) are completely different products.

The RS MPPT and Multiplus 2 inverter combination very much needs ESS loaded.

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micmak avatar image micmak nickdb ♦♦ commented ·

Good point, the RS naming confused me.

Which means, unfortunately, that I still don't have a solution for my problem... ESS doesn't work properly with my setup except when I choose Keep Batteries Charged.

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nickdb avatar image nickdb ♦♦ micmak commented ·
If your GX is reporting assistant not found, then it has not been loaded on the multi.

4.98 is also quite old now, I would update to current assistants and FW.

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