question

gyrex avatar image
gyrex asked

On the MultiPlus II, is it possible to completely disable charging batteries from the grid and only use solar?

I'm currently planning the following configuration below


In this scenario, is it possible to completely disable charging batteries from the grid via AC-In and only use the solar panels connected to the BlueSolar & excess power from the PV grid-tied inverter connected to AC-Out to charge the batteries?

Many thanks in advance for any help.

MPPT ControllersMultiplus-IIbattery chargingsolarFronius
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2 Answers
Rob Duthie avatar image
Rob Duthie answered ·

Hi

Yes it is, just setup the ESS correctly to suit, this is how mine works, and only charges from the PV not the grid at all. Read the ESS manual for the CCGX etc.

Regards

Rob D

NZ

4 comments
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Thanks for your help Rob. I can see at 4.3.9 in the manual here: https://www.victronenergy.com/live/ess:design-installation-manual#gx_device_-_ess_settings

It states:

4.3.9 Limit charge power

This setting limits the amount of AC power used by the Multi for battery charging. The limit also applies to AC power received by the Multi from a grid-tie PV Inverter.

In other words, this setting limits the flow of power from AC to DC.

  • This setting does not reduce the charge power coming from MPPT Solar Chargers.

  • This setting only applies to utilities connected to AC-in: In inverter mode, the 'charge-current setting' - as configured in VEConfigure - is used to control power coming from grid-tie PV Inverters.


There appears to be some potential contradiction here in terms

1. "The limit also applies to AC power received by the Multi from a grid-tie PV Inverter"

2. "This setting only applies to utilities connected to AC-in"


Apologies if this is a stupid question but I just want to double check I understand this, especially the last point. Assume that the 'charge-current-setting' is set to 0. Does this mean that per my diagram above: if I have a grid tied PV inverter connected to loads on the the AC-out, that any excess power which isn't used by loads on the AC-out will be used to charge the batteries but no power will be drawn from the grid via AC-in to charge the batteries?

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Hi

That is correct.

Regards
Rob D

NZ

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Thanks for your help Rob, I really appreciate it mate. I hope you can understand my confusion relating to the contradictions(?) in the guide.

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Hi

Yes they are a bit confuted, and there is so much to take in compared to other brands, as this a open source type product so are the many request and changes along the way. but the product does work very well. as a ESS system.

As i have not had a power bill for about 5 months and in credit with the power company, as i use the 10kw battery pack to supply all my loads an night time etc. It just works well.

Regards

Rob D

NZ

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Jens Rephöhler avatar image
Jens Rephöhler answered ·

Just a question regarding that setup: is a 15 kW Fronius suitable for a 3 phase setup regarding 1:1 rule ? So the rule applys to the wohl 3 phase setup and not a single MP-II ?

I ask this because i will update my setup to 3 phases soon and i use a Fronius 4,5-M3 till now. Am i able to use 2 more of these guys in the future ? (will be near that 15 kW Limit)

Thx

Jens

1 comment
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Hi,

According to the 1:1 rule, your total inverter power must be equal to or greater than your grid tied PV power capacity. Since I'm planning on running 5kVA MP2's on each phase totalling 15kVA and my Fronius grid tied inverter has a capacity of 15kW, I'm adhering to the 1:1 factor rule.

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