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snoopv avatar image
snoopv asked

SmartSolar, Multiplus and BMV-712 - How to link and sync charging

Hello!

At the moment I am planning a small setup with the following components:

- SmartSolar 100/50 with one or two solar panels (approx. 500W).
- MultiPlus 12/500/20 or 12/800/35 for AC and to support charging from grid.
- 12V LiFePO4-Battery with a BMV-712 Smart attached.

It should roughly look like this:

victron-skizze-smartsolar-bmv-712-multiplus-vesmar.png


The setup should stay as slim as possible, to save cost an overall installation space.

For the controls I also don’t want to get too fancy. The only needs are a Switch (to turn AC on/off) and a Display for SOC (BMV-712).

Settings should be done via Victron Control app.


So the goal would be to sync the power delivery and charging between the two devices (SmartSolar and MultiPlus)

Example:
The SmartSolar is set to limit battery charge current to 20A.
The BMV-712 supplies the information needed like the actual charge-rate (via VE.Smart networking).
So even if there is some other consumption at the same time charging current for the battery would not exceed 20A.

Q: How can the MultiPlus be fitted into this setup so that it does not overcharge in case the SmartSolar already supplies enough power but it can “help” charging if there is no / not enough solar power?

Q: Is there an easy way to link the MultiPlus to the SmartSolar or the VE.Smart network?
The VE.Direct Connector would be occupied with a VE.Direct TX Output Cable. Virtual load output is needed (see my other post here).

Help and hints appreciated!
Thank you.





BMV Battery MonitorMPPT SmartSolarmultiplus ve.busVE.Direct
victron-skizze-smartsolar-bmv-712-multiplus-vesmar.png (45.0 KiB)
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2 Answers
snoopv avatar image
snoopv answered ·

To sum it up:
Possibilities to link and sync charging between MultiPlus and SmartSolar:

To get most comfort and setup options:

  • Set up DVCC "… that needs a GX device (or a raspberry Pi running Venus OS)."
    see answer from @Matthias Lange - DE

or

  • Upgrade to a MultiPlus II with GX included (24V and 48V only)
  • Upgrade to a EasySolar II with GX included (48V only)

or

If nothing of the above is appropriate and you are happy with less setup options there seems to be a possibility with a lighter setup:

  • Do not link the devices, but manually limit charge current at MultiPlus according to what your battery needs at max.
  • Connect SmartSolar to a BMV-712 (eg. via VE.Smart) and it should automatically adapt its charge current.*
    --> That way if the MultiPlus already serves enough charging current the SmartSolar should not charge more and therefore prevent over charging. ✓
    It is not possible to change charging priority then.

    *documentation of a VE.Smart network states

That said…
[feature request]
... maybe that the small MultiPlus 500VA-1600VA series might get VE.Smart networking support and then be ready for synchronized charging some time!? :)
*fingers crossed*

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Matthias Lange - DE avatar image
Matthias Lange - DE answered ·
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snoopv avatar image snoopv commented ·

Hello Matthias.

Thanks for your quick reply and the links.

I was hoping that there is some slim and easy way to solve this without the need for additional devices and installation space. But since the MultiPlus is not VE.Smart compatible it seems impossible at the moment.

So the available options are:

- Extend the installation with one of the GX devices you suggested.

- Let the MultiPlus run without link to the other devices (SmartSolar, BMV) and set a hard limit for charging current.

- Use some other all-in-one device (MPPT, Charger, Inverter) instead of MultiPlus and SmartSolar, like the Victron EasySolar.
But unfortunately even the smallest device of this series is still too big for my needs. And I have found no 12V version either.

Thanks so far anyways! :)

You think the MultiPlus series could get VE.Smart connectivity in the future?

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Fideri avatar image Fideri snoopv commented ·

@SnooPV

Have you explored the Multiplus GX and the EasySolar GX?

F.

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snoopv avatar image snoopv Fideri commented ·

Yes I did. And theoretically you are right that MultiPlus GX and EasySolar GX would bring that functionality.

But: As I said, these devices they are not 12V, and enclosure dimensions are far too big for my installation space.
It's has to be a slim setup.

The small MultiPlus 12/500/20 would fit perfectly but it does not bring GX support and has no VE.Smart support unfortunately :'(

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snoopv avatar image snoopv commented ·

Extend the installation with one of the GX devices you suggested.

Unfortunately your suggested solution brings me to another problem as I am reading the 11.2. DVCC Requirements.
"If DVCC is not mentioned in notes relating to your battery, do not enable DVCC."

My LiFePO4-Battery unfortunately is not listed in the compatibility list.
It is a simple 12V LiFePO4 BatteryPack with an integrated BMS but no communication port or the like.

So what if I added the BMV-712 Battery Monitor to the Battery, would it work then?


... or is it pointless to add a GX device because Distributed Voltage and Current Control (DVCC) is still impossible.

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Alexandra avatar image Alexandra ♦ snoopv commented ·
@SnooPV

That note you refer to, mentions the compatibility list by the way, so batteries tested by victron. That note refers to those batteries not your battery. They are saying if the online manual (for the compatibility list) written by victron does not say to enable DVCC, then don't.


DVCC for non can connected batteries will still make a system wide charge current limit which is what you are aiming at if i understand your post correctly.

See features for all systems.

I use DVCC for systems with 'non compatible' batteries. No problems to date and we are talking years of use.

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snoopv avatar image snoopv commented ·

@Alexandra
Very nice to know that it works in other constellations. Thx for that hint!

Maybe i took those DVCC requirements too literal when reading. So to say as a must and not as a recommendation.

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