DIY Setup Victron Multiplus II GX

DIY
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1

Hi, I am new here. I am looking to build a setup at home which will allow me to charge batteries at night and use them during the day, at this time I am not too worried about solar, and could add this later. My idea is to use a Victron Multiplus II GX with a Fogstar 32KWH battery pack, and a Cerbo GX with 5 inch screen.

Grid power going through a dedicated small consumer unit - 50amp into the Multiplus II GX, then the output 1 of the Multiplus II GX into the main consumer unit for the house - setting up through the Cerbo GX to only charge at night, allowing the batteries to power during the day, but dropping back to the grid once the batteries run out. Does anyone have any experience in a setup of this nature and could give any advice, or any diagrams they could share.

Many thanks in advance. Stuart

2

I have done a few that have selective discharge times with no solar.
You can use the ESS assistant (programmed on the inverter) and scheduled charge on the GX so it easy to interact with after basic set up.

Since there is notmich to your system there won’t be a diagram really.

Are the loads you want to offset before (on ac in) or after the inverter (ac out)?

If you want to use the cerbo just get a multiplus without the GX. You can’t have 2 GXs in the system

3

Just to add that if you are in US, ESS may not be an option. Otherwise, I agree with @lxonline that it is the way to go.

4

if you use a MP2 GX, no need for an extra Cerbo

GX Variants habe something like a small Cerbo already integrated

5

Thanks for your note. Not sure what you mean by offset before or after the inverter? Could you go into some detail?

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In the UK. So working on cheap electric at 23.30-05.30.

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Some people have no load on the output of the inverter but feed backwards into the house frlm the input.
I think it is safe to say that is probably not what you had in mind though.

8

Nice. Definitely worth offsetting like that.

9

@stuartseeley Couple of important things to note. At 70A DC charging you will only be able to fill around 2/3 of the battery bank, but unlikely as such prolonged charging will produce a lot of heat and also derate the system a fair bit. Not being able to fully charge the batteries may result in balancing issues over time. Pay particular attention to the DC disconnect switch and wiring and opt for a Jean-Muller fuse holder and disconnect combined as DC switches overheating is a well covered topic in the forum. Considering heat and conversion losses, the actual benefit from it is maybe only about 50% saving and offset against the capital investment not going to get you your money back anytime soon. It does however offer some energy security potential and backup functionality depending on how you wire it. In essence as others said it is a simple ESS with scheduled charging and just no solar. Did this for over two years until I added solar.