question

bitcrusher avatar image
bitcrusher asked

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 gxmultiplus ve.bus
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

4 Answers
Ed Jones avatar image
Ed Jones answered ·

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)
2 comments
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Kevin Windrem avatar image Kevin Windrem commented ·
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.
0 Likes 0 ·
Show more comments
bitcrusher avatar image
bitcrusher answered ·

Yes !

That’s it, I got it! Yehaw !

Thank you very much!


2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

bitcrusher avatar image
bitcrusher answered ·

...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)
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

penfold1970 avatar image
penfold1970 answered ·

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 ?

2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Related Resources

Cerbo GX product page

GX family product range

Cerbo GX & GX Touch datasheet

Cerbo GX Manual

Venus root access document

Additional resources still need to be added for this topic