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xtopher avatar image
xtopher asked

Multiplus II 3000 ESS/solar questions

I am looking at the possibility of creating an ESS using a Multiplus II (maybe GX?) and Pylontech batteries, growing the system over time as required and adding solar in a later phase. I would be looking to utilise our Octopus GO tariff initially to charge the batteries on our cheap rate and run down the batteries the rest of the day. I am happy the 3kva model will suit our requirements for powering the majority of loads in our house and accepting some energy from the grid as required for those that require it (induction hob etc). Our daily consumption is very modest at 10kWh for the house power. We have a Zappi and Eddi already also, both using the GO off-peak to charge the car and DWH (an average of 10kWh/day ea.), so once solar is commissioned in the future I would like to use excess solar to divert to Zappi and Eddi as well as the batteries.

I have numerous questions on different subjects so not sure they should all be asked in a single thread, please let me know and I can split them.

This is a UK install

  1. Multiplus and batteries (Phase 1)
    1. G98 - Our initial install will be just the MPII and batteries, configured to be self consumption so no export back to the grid - does anyone know if this would still require G98 declaration? I assume it would as its still hooked up to the grid and has potential to export
    2. In the UK my understanding is that I can get a spark to wire up the circuit ready to connect the MPII to satisfy Part P regs and then I could connect the MPII/batteries and make the final connection to the circuit - is that acceptable? Especially from a G98/DNO declaration perspective? It appears that you dont need to be certified but DNO paperwork asks about certifications.
    3. Is it reasonable that this can all be done DIY with a spark to commission the circuit? I've done similar config of devices in the past (had to reconfig our Zappi from scratch as it was configured wrong when installed, installed/configured our Eddi, have a home automation setup that I created), work in IT, etc. I'm not sparky but happy I can learn what I need to make a safe install and configure the devices. Given most of the time I spot the errors of other trades people I'm quite confident. Signed up for the Victron professional portal for learning already!
  2. Solar addition
    1. Given the requirement for excess solar to go to the Zappi/Eddi, is it possible to use MPPT solar array and have the MPII send excess solar to the Zappi/Eddi but NOT use battery energy? As MyEnergy will see this as a single AC input for battery and inverter, I am assuming not? In which case I would be limited to a separate grid-tied solar inverter to any energy I would want to divert to the Zappi/Eddi? I think it would be too complicated for it to understand that house loads should be provided from solar and battery but only excess solar to the Zappi/Eddi - to save the batteries for later in the day when there is no solar. With an separate AC solar inverter, I can see that I can set the MyEnergi side to only consume any excess that would be going to the grid, which can initially be hoovered up by the batteries for charging, then say Eddi, then Zappi. Or perhaps you can by telling it to keep the batteries at 100% when we have solar or keeping a certain percentage back for evening use?
    2. G100 - I've seen that the MPII can be G100 certified, by using CCGX and wired AC sensor (in the CU) - https://midsummerwholesale.co.uk/pdfs/victron-g100-declaration-multi.pdf - can this also be done using an MPII GX and CT clamp instead of the CCGX and hard wired AC sensor in the CU? I don't currently have space in the CU so an external clamp would work better, but appreciate that can effect the G100 certification. We arent currently looking to get MCS installer so wont get SEG, so if we can keep it on a G100 certificate then we don't need extra permission from the DNO once they are happy with it? Like a G99 'lite' application is my understanding, if they are happy it works then they treat it as a G98 setup as they know there will not be any export over 3.68kw?


Multiplus-II
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2 Answers
Paul B avatar image
Paul B answered ·

I suggest that you go to your local Authorised Victron agent that you are looking to purchase this off and I am sure they will advise you - you have a lot of lacal area questions so best to ask locally as different areas and localities/countries have different requirements

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dansonamission avatar image
dansonamission answered ·

How are you getting on with this? We're looking to do the same.

The 48/5000 is listed as both G98 and G99.

https://www.ena-eng.org/gen-ttr/Index.aspx?Action=ViewDetail&EID=42775654&tab=search

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xtopher avatar image xtopher commented ·
Currently in talks with a couple of resellers on the best setup.


I don’t see how they can list the 48/5000 as G98 when it is over the 3.6kW (16A) per phase limit? Guess it meets all specs other than that?! Maybe it can be limited to 3.68kW?

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dansonamission avatar image dansonamission xtopher commented ·

The export can be set to zero if required.

You’d be better off installing a ET112 meter on your incoming supply.

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dansonamission avatar image dansonamission xtopher commented ·
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