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UK off grid home


We have the aim of going off grid solar/gen with our UK home, which is entirely electric due to our location. The rear of the house faces South with no shadow, at 52 latitude and we have daily usage figures going back 30 months. I have daylight hours for our latitude, actual usage figures for appliances, ~100sm of roof and an idea of what we want.

Having wired the house all rooms are on seperate split socket/light circuits and all heavy draw items are on seperate circuits. We run split CU and already have a gen which we can switch to when grid power fails for longer than my UPS can handle.

I have a rough idea of the system we want but we want to install it in two stages. Reasons are, monitoring that the system is actually doing what we think it would, switching over the house to a split system, building work which needs to be completed, incorporating an existing Gledhill thermal store and time...

We have a day van which was we fitted with Victron so we have experience.

Aiming for 2x Quattro, 2x MPPT, 15kWh actual battery, plus VE stuff etc...

Has anyone else done a whole house UK off grid? Will Victron or other check over my design? Basically any pointers please!

We want to convert our multi sheet spreadsheet into reality :-)

dick-murray asked
Alistair Warburton edited ·

2 Answers

Generator running indication? (manual start... for now)

Hi folks,

New to all this, stem less than 24 hrs online.

Easysolar 5000, BYD 13.8

Seems to be working well but not showing generator running when charging.

I am assuming that is because I am not starting the gen from the system, yet, but I wanted to know if I can get it to recognise when the gen is running base on the AC state.

I am off grid so there is no AC unless the gen is on.

If there is no setting for this, is ther an aux input I can configure to do it?

Alistair Warburton asked
Alistair Warburton answered ·

6 Answers

Vorrang von MPPT Ladung bei Inselanlage

Guten morgen,

die betroffene Inselanlage besteht aus einem MPII, zwei MPPT Ladern, einem Cerbo, BMV und Bleibatterien.

Bei Tagsüber angeschlossenem Landstrom hätte ich das gerne so konfiguriert, dass die PV Ladung priorisiert wird, der Multi soll erst laden wenn die Sonne weg ist.

Läßt sich das irgendwie konfigurieren?


Martin asked
netrange commented ·

2 Answers

MPPT jeden Tag neuen Ladezyklus vermeiden


bei einer Inselanlage mit Bleibatterien, MPII und zwei MPPTs bleibt bei angeschlossenem Landstrom der Multi über nacht auf Float. Sobald die Sonne raus kommt, starten die MPPTs einen neuen normalen Zyklus mit Bulk, Absorption und Float.

Kann man dies zur Schonung der Batterien vermeiden?


Martin asked
Matthias Lange - DE answered ·

1 Answer

Flimsy regulation of frequency shift & Charge current limitation in ESS offgrid mode

I have a system running with a Multiplus II 3000/48 and 8kWh LiFePo battery, and a Fronius Primo 3.0-1 PV inverter. The Microgrid setup on the Fronius is active and the system is working properly overall, also the power reduction via frequency shift works in general.
However, I find the regulation of the frequency shift to be not optimal. While the rate of frequency change was mentioned many times, another problem is the amount of frequency shift.

Since the Multi can provide 35A max. to the battery, that is about 2000W AC in, it's never neccesary to lower the power of the Primo below that 2000W, hence the frequency should never have to rise above ~51.6Hz (unless the battery voltage reaches it's maximum).
However if the AC load or sunlight is fluctuating only a tiny bit, the charging current will rise above 35 Amps and the Multi will "panic" and rise the frequency to 52.7 instantly, killing the Primo and it will take a long time to return to normal, which is in most cases at ~51.1 to 51.3Hz with a bit of AC idle loads.

Why is the regulation this way? The Multi knows the maximum PV inverter Power is 3000W, so technically it should know that rising to ~51.6 Hz would be enough, even in the worst case.

Since there doesn't seem to be a way to solve the problem directly, I've tried to lower the charging current, so the regulation has a bit more room for error. However, I found that neiter lowering "Charging current" setting to 33 Amps in the calibration, nor setting a "Charging power limit" in the control settings is affecting this regulation in ESS - No grid mode, it always tries to maintain 35 Amps.

Why are these settings only working while connected to a grid?

Thanks for your help!

kaffeetasse asked
Alexandra commented ·

0 Answers

Grounding Off-Grid System - Some questions

Hello everybody,

in the past few months I've been designing the off-grid system for my farm, with the help of an electrician. I already bought (almost) all the components and I'm installing it right now.

Now, I find myself stuck with the grounding of the system, because I'm not quite sure how I should wire the whole system so that it's as safe as it should be.

As a side note, consider the following:

  • I know that it is advised to ask this kind of questions to a qualified electrician who knows the local regulations, but believe me, where I live (rural Panama) it's actually pretty hard to find one, let alone someone with experience with Victron products. In fact, I had to buy 80% of my components from the US because nobody sells them here. (for example it was literally impossible to find flexible wires, I had to buy them on Amazon. Same for 4/0 copper wire lugs and the tool to install them)
  • regarding local regulations, forget about it, there are no specific regulations and nobody checks whether what I'm doing is good or not. The person in charge in this town does not know anything about off-grid systems, and is in fact waiting for me to complete my system so that he can see how it works

I had some help from en electrician online, and of course I studied all what I could find online, but there are some things that I'm not sure about, so maybe you can help me out.

Please find attached the diagram of the system (It's a work in progress).

Electrical Drawing with 1x BYD LVL.pdf

I believe that the grounding wiring needs to be fixed, because:

  • 6 AWG for grounding the inverter is too small of a wire, because from reading Wiring Unlimited I think the wire should be tick enough to be able the carry the full current, which in my case is 250 amps, so the wire should be 4/0 AWG
  • it's not clear what happens between chassis grounding and AC grounding. Is it a floating system? Do I need one RDC before the AC distribution? Does the PV part of the system have a dedicated ground rod for lightning protection?

This is where I'm stuck.

From my understanding, I think the grounding should be fixed as follows:

  • the metal frames of the PV panels should be grounded with a ground rod
  • the ground output of the PV combiner box should be connected to the same ground rod
  • all the chassis of the components (the two inverters and the charge controller) should be connected in parallel with tick wire, and then connected to the central ground terminal of the Lynx Distributor
  • from there, I should run a 4/0 AWG wire to a ground busbar (not shown in the diagram), where I should also connect the grounding wire for the AC distribution panel
  • this ground busbar is connected to another dedicated ground rod
  • there should be a RDC breaker between the inverters and the AC distribution panel.

Well, there's that, not sure what I'm missing, but I'm sure that something is missing in my understanding of the whole grounding deal.

I appreciate any help!

Edit: I added a screenshot of the diagram.


niccolaiddis asked
johnsmith edited ·

5 Answers

Cerbo GX off grid usage

I have a 50 amp RV that I put a Victron Multiplus II 2x120, MPPT 150/100 with 1200 watts of panels in series, and a Cerbo GX with DVCC setup. Now because I have the Cerbo installed, my bluetooth view of the Multiplus is devoid of any useful information. This is fine while it is sitting in my garage attached to my home wifi and I can use the VRM to view what is going on. My issue is when i am not at home, driving down the road or in an off grid situation (which is a lot of the time). Is there no way to use Bluetooth to get a system view of what is going on in that circumstance? When I bluetooth to the Multiplus it shows me nothing because it is hooked up to the Cerbo GX, when I bluetooth to the Cerbo GX I get a very unsatisfying view of nothing except wifi settings that do me no good at that moment. Why doesn't the cerbo gx bluetooth expose a way to view the remote console? Or does it and I somehow have it misconfigured?

twtch76 asked
seb71 answered ·

2 Answers

GlobalLink 520 Uk coverage

I’ve just ordered a GlobalLink 520 for remote monitoring of my boat solar but can find a difinitive map coverage for the uk. Mainly Gloucestershire.

Has anyone got one in the uk?

Simon Coram asked
Simon Coram answered ·

5 Answers

Why can't I use ESS in off grid?

I would like to know what is the technical difficulty of having an off grid system running in ess mode. If ess can work as aback up for a week because of grid failure of one week, it is effectively running as off grid. So what would be the complication of that?

Bart asked
nickdb commented ·

3 Answers

Battery voltage drop when high load is connected


I have installed the following off-grid system, which has been working pretty good for one year.

  • 4 300W solar panels
  • SMARTSOLAR MPPT 150/35 48V
  • 8 Acid Lead batteries of 6V each (Deka GC15)

However I'm wondering if the behavior I see when I plug a 1200W water heater during the central hours of the day is expected.

As you can see from following graphs the battery voltage drops when load is active and jumps back to an higher value afterwards.

Reading other posts on this subject I've got this is expected indeed, but my question is: do I have to worry about this voltage drop? In other words: should I power on the AC generator if the battery voltage goes down to 46V like in the picture below?

Thanks a lot,




the-salmon asked
nickdb commented ·

3 Answers

Getting Genstart to trigger on excessl load on 3 phase using Genflag

Three phase multiplus system (6 x 3kva multis) Wish to self consume, have the multiplus only charge from grid on battery level or excessive load. There is solar PV on AC out so PV Assistant is also required, and driving need for system to be group switched. Grid AC (3 phase) is avialable to AC IN .

Do not want to use ESS, as I do not want to put in grid code and risk feeding any of my power into the grid.

If I load Genstart and Genflag on phase 1 then that works for low battery and excess load on that phase , only. Excess load on L2 or L3 cause Multis to overload. The Genflag seems to be distributed somewhat to the other phase multis since they dont start charinging, probably via group switch function. I cant get Genstart to trigger for overload on L2 or L3. IF I load the assistant on another phase , nothing happens. If I load the assistant plus another instane of Genflag then I lose function on L1 too.. seems the Genfag on L2 or L3 is Or'd with L!. I can prove if I put both assitants on L2 or L3 then the genflag does control the Ignore AC flag on that multi.(changes from 1 to 0) . but when triggered nothing happens.. presumbably because it is still 1 on L1 and that is charge / phase master.

Any ideas how I can use these assistants and genflag to trigger for overload on L2 & L3?

mblowes asked
mblowes commented ·

0 Answers

Wiring help Truck with 48v system Questions

1. What fuses or breakers do i need and where?

2. Is the wiring right or does something need to be moved or added?

3. Shunts, Cerbo GX, etc needed?

4. Lynx 1000 needed?

5. This will be completely off grid

6. Is MPPT needed for EasySolar 2 GX?

7. Winch straight to battery or connected to paralleled Orion-Tr’s?


Updated down below



lpez210 asked
lpez210 edited ·

4 Answers

Victron Multiplus II with feed-in (while grid on) and blackout operation

Hello there!

I am trying to figure out something rather simple but can't find the answer:

* The system is a three-phase system with three Multiplus II 48/5000. There is also a Fronius Symo 8.2 connected at the AC OUT of the victrons.

* Grid is connected to the AC IN (Spanish grid).

* Victrons have a 20 kWh BYD LVS battery.

We want to allow exporting all excess energy towards the utility grid, while the grid is available.

If the grid fails, we want the system to keep running, without feeding any excess to the grid, and regulating the power output of the Fronius Symo, in order no to overcharge the batteries.

What would be the recommended settings for VE Configure/ESS? Would I need anything else like an external contactor? If the Grid code was configured to Spain, will the Victrons still work in the case of grid failure?


mm-azimut360 asked
lifeingalicia answered ·

1 Answer

Off-grid generator power output issue! Advice wanted.

When my generator is running (after auto or manual start), the power it outputs is not steady and doesn't seem related to AC loads or PV Yields. Occasionally, for reasons I cannot discern, it does produce a high and steady output. When the output is steady the batteries can charge from 20 - 90% in around 2 hrs. When output is irregular (in identical PV weather conditions) batteries can take up to 4 hours to charge.

Does anyone have any advice on why this might be happening and how to fix it? My installer doesn't have a clue.


Off-grid System overview for context:

1 x Victron-EasySolar 48/5000/70-100 inverter
12 x NeOn2 LG350N1C-V5 solar panels
2 x PowerPlus ECO4840P batteries
1 x DIESEL (AIR COOLED) 7KVA 1 PHASE - Generator (Auto-start)


michael-m-b asked
JohnC answered ·

1 Answer

Multiplus-II power consumption invert/on-Grid


Hi folks!

In the last days I did some research about my ESS system with the MP2 48/3000. In this research I found out, that the system is able to charge the battery also on inverter-mode with excess power on grid. What I also did found out is that on inverter-mode the MP2 consumes almost twice the power it does when being on-grid with 10W cont. power to grid. I know that ESS isn’t configured to work off-grid but if it works that well that may be a consideration. Or does that affect the warranty?

As you can see on my screen, there is the AC-input, which I want to minimize as much as possible. When AC-in = 0 then the consumption (even with my devices on standby) is almost twice as high. Is that due to an higher consumption from the device itself or is it because of a bad reading from the internal AC-in measuring device?

Thanks in advance,


Google LocalGuide asked
Google LocalGuide answered ·

1 Answer

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