Force multi to charge, although AC input control is activated

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bitcrusher asked Sep 30, '21

Force multi to charge, although AC input control is activated

Hi there,

In my campervan, I use a Multiplus Compact 2K, and a Buckboost connected to a Cerbo.

Normally I have set the AC input control in the multi on, that it will only load the lithium, when SOC goes < 60%. And it should stop after "end of absorption". So far so good.

Is it possible, to force the multi to charge anyway (no matter what SOC) in special situations, e.g. if I want to start to a camping tour with full battery?

another question: The multi get's its SOC for AC input control over the cerbo (VE.Bus)?, but the SOC for "switch off - condition" must be calculated internal?

Why is it not possible to configure the multi completely over the cerbo? It's a little cumbersome to use MK3/usb interface for the multi ;-)

Thanks for your help!

cerbo gx multiplus ve.bus

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Ed Jones answered · Oct 03, 2021 at 06:01 PM

Yes, @bitcrusher it is possible and not too difficult to do, however it's not very intuitive. I'll give you the settings I use. If you read up on using assistants with the MultiPlus plus my notes below, you should be good to go.

I use a Multi-Plus 3KVA, Cerbo GX, a BMV-712 and some other misc Victron gear. I use the BMV to give me battery SOC, temperature, voltage, etc. and I have the battery monitor turned off on my Multi. I also wired up a SPST toggle switch and relay 1 on the Cerbo (in parallel) to the Aux 1 input on my Multi. This way I can manually turn off Ignore AC with the toggle switch and/or use the generator start/stop function in the Cerbo. You'll need to make sure the Virtual Switch is turned off on your Multi, also, and use the Cerbo instead for configuring Ignore AC based on SOC, load, etc.

See attached PDF with screenshots I put together for you.

HOW-TO - Override Ignore AC.pdf

As for programming the Multi via the Cerbo, that is also possible. Read up on how to use Remote VEConfigure.

how-to-override-ignore-ac.pdf (1.5 MiB)

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Kevin Windrem commented · Oct 03, 2021 at 06:25 PM

The Multi Compact does not have an aux input but it does look like you can use the temperature sensor input as an aux input when programming the General Flag "relay" in the HOW-TO above.

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Ed Jones Kevin Windrem commented · Oct 04, 2021 at 09:23 PM

Thanks for adding that great tip, Kevin.

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Modifications Space

Node Red Space

Answer 1 · 2022-02-20T20:28:26Z

bitcrusher answered · Feb 20, 2022 at 08:28 PM

Yes !

That’s it, I got it! Yehaw !

Thank you very much!

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Answer 2 · 2022-02-21T09:42:12Z

bitcrusher answered · Feb 21, 2022 at 09:42 AM

...just another question ;-)

when I control the "AC ignore "function with the assistant and aux relay, by the cerbo's "genreator relay" as you described in your pdf (great idea! thx!)...

I still miss the function, to stop charging "when absorption is finished". I can only stop the "generator" (in this case AC input) at SoC 100% - but it should let it open for balancing. There's also no "additional time" that can be set (like in the "loads-condition")

Thx!

...aah, just one more question ;-)

may it also be possible to set up the Aux input for "ignore / not ignore", and set up the conditions via MK3 interface and victron connect? (not via the cerbo / genset menue). In this cas i would use a toggle switch (as you did) to set up between ("ignore" / "not ignore")

conditional.jpg

conditional.jpg (75.7 KiB)

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Answer 3 · 2024-01-24T12:44:38Z

penfold1970 answered · Jan 24 at 12:44 PM

Hi @Ed Jones

This is very interesting to me and having read the pdf find it very impressive, do you have a wiring diagram for the switch/relay/aux input you could post please ?

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