Multiplus II only using grid, not battery

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366cobra asked Sep 15, '23

Multiplus II only using grid, not battery

Hi,

I have been using the Multuplus II for about 1/2 year with lead acid batteries and it has been working fine.

Now i have switched to a 24V 912Ah Lifepo4 pack and have issues with the inverter only using grid power.

the batteries are at 100%, but the inverter ignores it and only uses grid. the only way i can use the batteries is by removing the grid connection. then it has no issues using batteries.

i have reset the setting via my notebook and all, but it still does not want to use the batteries.
there must be something i am missing, as before, it would deplete the batteries, change over to grid and then back to batteries once we have enough sun.

Am also using Venus OS and it shows me only the error for inverter, nothing else any more.
it usually shows me the victron smart shunt and victron MPPT 150/100 as well.

would be great if someone has any pointers.

Thanks

Martin

Multiplus-II grid

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Rob Duthie commented · Sep 15, 2023 at 09:29 PM

Have you set the ESS setting to battery optimized without life?

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366cobra Rob Duthie commented · Sep 15, 2023 at 10:23 PM

Hi Rob, i have not touched that setting yet. want to get it working like it was first

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Answer 1 · 2023-09-15T22:16:14Z

danqcca answered · Sep 15, 2023 at 10:16 PM

Do you use ESS with Keep Battery Charge? Adjustable on the Cerbo GX If yes, it will keep battery full charge. You must use one of the 2 Optimized Mode

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Answer 2 · 2023-09-19T06:40:37Z

366cobra answered · Sep 19, 2023 at 06:40 AM

my last post did not save, so here it is again.
i have verified and ESS is definitely not activated.
would it help for to upload my config file?

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Answer 3 · 2023-09-19T06:59:10Z

nickdb answered · Sep 19, 2023 at 06:59 AM

Without ESS, it will only use grid power unless you force the multi to invert.

If nothing has changed, it won't be any different to before.

If you updated firmware on the multi, it would have wiped settings.

Not enough to go on here.

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Answer 4 · 2023-09-21T11:00:33Z

366cobra answered · Sep 21, 2023 at 11:00 AM

I am pretty sure i updated the unit, so i guess you are right about wiped settings.

though, i am 100% sure that i had it working without ESS. to change the grid code you would need a password, but mine is still set to 'none' and you need to set a grid code to use ESS.

i had it setup in such a way that when my lead acid batteries went below a threshold, the inverter would switch to pass through and when the sun was up again and the batts were charging it changed back to batteries.

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nickdb ♦♦ commented · Sep 21, 2023 at 11:07 AM

You are usually allowed one change without a code, so if you're being prompted something was previously set.

That looks very vanilla - no lithium profile etc.

I would get veconfigure out and programme it with appropriate settings, and add ESS, if you intend the battery to be used for self-consumption.

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366cobra nickdb ♦♦ commented · Sep 21, 2023 at 11:10 AM

i do want to at some stage, but i cannot even find which of the settings for Australia is the correct one for me yet. the system needs to be legal

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nickdb ♦♦ 366cobra commented · Sep 21, 2023 at 11:50 AM

Use "other" so long, you can find the password by the power of google.

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Answer 5 · 2023-09-21T13:12:58Z

366cobra answered · Sep 21, 2023 at 01:12 PM

i just found the following:

"ESS is only possible when the unit is allowed to feed back into the grid"

i do not want to feed into the grid, just use the solar for my house. so i guess i cannot use ESS?

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nickdb ♦♦ commented · Sep 21, 2023 at 01:19 PM

It won't feed back unless you enable it to do so, which isn't the default behaviour.

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Answer 6 · 2023-09-21T13:42:46Z

w8dev answered · Sep 21, 2023 at 01:42 PM

You have nothing telling the inverter to not use the grid. By default the Multi-Plus will use the grid when it detects a grid connection.

Go to the Virtual Switch tab and select "ignore ac on input". Then you will see a few new tabs show up which will allow you to configure when you want the AC In to be abled and when you want it to be disabled.

https://youtu.be/Pt533oKjKNU?t=973

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nickdb ♦♦ commented · Sep 21, 2023 at 02:42 PM

This is inaccurate.

ESS is a grid-based system, you supply from battery (within parameters) and balance comes from grid, hovering around a setpoint which fluctuates with loads.

No, it will not backfeed unless enabled.

There is ebb and flow with power, load dependent, but electricity isn't uni-directional anyway.

If you don't want any grid usage, then yes, disconnect the grid and this can be automated so you are very efficient and have zero ebb and flow.

Ultimately it is designed for grid attached and isn't supported off grid.

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