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green-gear-energy avatar image
green-gear-energy asked

Solar primary source and AC as backup with MultiPlus

Hi to everyone. We have problems configuring the MultiPlus using the VE Config.

We want the MultiPlus use the solar power from the batteries and when SOC drops below certain percentage (50%), draw power from the AC-in. Then, when batterias are charged, disconnect the AC-in and get back to solar power as a primary source.

We have been configuring it using the VE Config and three assitant (2 programmable relay and a use of the general flag), but either way the MultiPlus still are using the power from AC-in ("mains on" light on). We have gone to configure it to load the configuration, the MultiPlus get restarted but it keeps the mains on, then we try again reloading the configuration and the MultiPlus change to inverter mode, but the client call us phew days later because the MultiPlus change back to "mains on".

We don't know if the assitants what we are using are right. If you need to know, the installed system use a BlueSolar controller to charge the batteries with 9 photovoltaic panels. There is no communication device like a Color Control or VBM between the MultiPlus and the BlueSolar.

We had been attached the settings of each assistant. The internal battery monitor is actived in the MultiPlus and we have been careful sending the configurations to the MultiPlus.

Any help wil be appreciate!


MultiPlus Quattro Inverter ChargerVEConfigure 3Assistants
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2 Answers
richard-mori avatar image
richard-mori answered ·

Considering that your stated scenario is fairly simple, I would probably just stick to using the virtual switch, and not use any assistants.


An example config is below:

This will ignore the AC input as long as the battery is above 50%. If it goes below, it will connect to the grid and charge the batteries to full, at which point it would disconnect from the grid again. You can can also add in conditions regarding load and voltage.


If you want more sophisticated control, or add an inverter on the AC output, then you will need to go back to assistants.


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bruce32466 avatar image bruce32466 commented ·

text deleted by moderator. cross-post.

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green-gear-energy avatar image green-gear-energy commented ·

Thanks for the help! Actually we were thinking in use a Virtual Switch, but not sure enough. We're gonna to investigate more to be sure, the installed system is pretty far from our office so we can't go so sudden or that much how we would like it.

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richard-mori avatar image richard-mori green-gear-energy commented ·

That's understandable. Just a note, what Daniël says is correct. The Mulitplus has no idea how much the charge controller is charging the battery, and can only see the current that it itself puts in and takes out. This means that the SOC reading will be meaningless so there is no point in having it. You can still do this control though, but do it based on voltage, not SOC. This is more primitive, of course, but the only option unless you shell out for a BMV or a GX device.

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Daniël Boekel (Victron Energy Staff) avatar image
Daniël Boekel (Victron Energy Staff) answered ·

Hi @Green Gear Energy

You say you use the internal battery monitor of the Multi....but the Multi doesn't know the solar panels are charging the battery through the MPPT, so the Multi sees energy used, and SOC gets lower and lower.

if you want to do this without a GX device, you'll have to use a BMV to monitor SOC and use the BMV's relay connected to an input of the Multi to ignore AC-in

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green-gear-energy avatar image green-gear-energy commented ·

Hi, Daniel, very thanks for your reply! Can we work a little more on this idea? I don't get completely the "logic" behind this but, why the Multi sees energy used from the battery if they are being charged through the mppt controller?

Is like the Multi sees a variable voltage on the batteries and because of that uses the AC-in?

Can we configure the BMV with VEConfig or Victron Connect using the MK3 interface?

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Daniël Boekel (Victron Energy Staff) avatar image Daniël Boekel (Victron Energy Staff) ♦♦ green-gear-energy commented ·

@Green Gear Energy

Please do some more research yourself, this is very basic logic.

Yes you can use battery voltage as a base for connecting to AC.

BMV: Victron Connect with ve.direct to USB cable

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