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MultiPlus ii 12/3000 - System info, Shunt Size and Earthing Requirements

Please see attached drawing for my proposed system - I have already bought the Multiplus ii 12/3000 and 4 x Bosch L5013 Leisure batteries.

I have seen in the Victron wiring unlimited info that the 12/3000 may need a 1000a shunt, is that correct or will a 500A be sufficient? I was planning to buy a smartshunt.

Wiring to/from the inverter and battery bank interlinks are 2x50mm2 with 2 x 200A fuses to protect the inverter connection. Also a 300A on the negative side of the leisure battery bank to protect that from vehicle short. Are any other fuses required/too small or large/in the wrong places? Hopefully my drawing is clear enough!

Also I have read about it being undesirable to go from TT to IT in terms of earthing arrangement, do I just run the CU earthing to the vehicle ground which is also connected to the earth of the inverter? I presume the inverter deals with fault current by linking the neutral and earth internally when the shore power is disconnected?

Any advice relating to any of that is helpful, thank you in advance! Is a BatteryProtect a good item to add to the system also? Where would this go? is anything else worth adding? I want no displays internally, all off the phone if possible, to go in a 7m class A motorhome.


joe90k asked
joe90k commented ·

2 Answers

UK Installer List

Hi, New to the group. How do you find an Victron installer/engineer in the UK please. North West England ideally.

Thanks, Clay

manicorganic asked
daza answered ·

5 Answers

ET340 in / out (sanity check please)

Hi All,

I'm about to install an ET340 and now insanity has kicked in.

My brain is telling me that the bottom of the ET340 (pin 4, 5 and 6) are IN (coming from the main switch/provider), and pin 1, 2 and 3 are OUT going to the "house".

However. Looking at the side of the ET340 the arrows are pointing the other way.

Anyone here who can tell me what the correct direction is?

Thank you.

Noel asked
Noel edited ·

2 Answers

Multiplus II shut down - fault? Help please

Hi all,

I have a new Multiplus II 48/10000/140 and it worked fine for 3 days then all of a sudden it shut down. It triggered the short circuit protection on my batteries and the AC pass-thru doesn’t work either, it just sends the AC for a couple of seconds and then stops.

I’ve disconnected the batteries and tested those and they’re working fine and the short circuit alarm clears as soon as they’re disconnected.

The battery terminals on the multi show as a short circuit on my meter but I read this could be due to the capacitors and the resistance does increase the longer I hold my meter on. However, if I connect my Cerbo to the battery terminals on the multi with 51v that isn’t able to draw power either but works fine powered from another source.

Does anybody have any idea what’s going on and how to fix this or is it likely a faulty unit?

Thanks very much,

jamietb asked
Alexandra answered ·

2 Answers

Advice on Multiplus and Pylontech home setup


I am a keen beginner in becoming more power self-sufficient and am planning a battery/inverter/solar system.

I have included a diagram of the sort of setup I want to go for to be able to make use Victon equipment and Pylon-tech batteries to create an ESS to take advantage of cheap electricity tariffs at night here in the UK and power my house during the day through the use of a Mulitplus II inverter while also using power generated from solar for additional power and storing it using batteries. I am not at this stage wanting to feed back and export any additional power that's generated.

After reading a lot of Victron documentation and watching a fair amount about this I think I have got the general idea about how to set this up but have a few questions about the specifics of what I need which I was looking for help on.

I plan on leaving the current consumer unit in place and using it to power any heavy load items that might be needed and then using a circuit on this main consumer unit to feed into the A/C in of the Multiplus.

I am wanting to go for a Multiplus 15000/48/200 so my first question is what size/gauge of wire and fuse/mcb/rcbo do I need to feed into the Multiplus from my current CU?

The Multiplus 15000/48/200 can handle a peak of 27 000 watt using a power factor of 0.8 for average household appliances, but I believe this is only for a short amount of time (0.5 Seconds), it also seems to be able to maintain 150% for 5 seconds (18000 watts) and 130% for 30 mins (15600 watts). After looking at my usage over the last 12 months this should be plenty for my whole house at any time even when cooking on the hob and oven, using the washing machine and dishwasher along with the microwave and kettle. Any heavy-duty loads could be added directly to the main consumer unit and used mainly at night when there is cheap electricity (EV charger) but after monitoring the house usage over the last year this should be within those numbers.

The maximum feed in power is 15000va so the unit can draw approximately 12,000 watts , at 240 volt this would equate to 50 amps, what size mcb do I need to feed in, should it be an rcbo or can an rcd protected mcb be used instead, should I use a 50 amp or 63 amp breaker?

What cable should I use here, the distance is around 5-10meters, can I get away with using 10mm2? my other option is to run 25mm2 tails as I am already planning on running 1 set from the henley blocks to the UPS consumer unit directly so I can make use of a changeover switch in the UPS CU to allow for maintenance or to be able to isolate the Multiplus out of the equation. Would 25mm2 tails be overkill which is just going to cause unnecessary problems when routing in the main CU?

For the A/C out from the Multiplus to the UPS CU should I use 25 mm2 tails or is this overkill too?

Would it be wise to add further isolation other than that provided by the change over switch and the master switch in the CU?

If so should I just use the same as (a) before getting to the change over switch (j)

Do I need a current sensor, ET112-1 (b) for the Multiplus to know whats going on in this setup?

If I don't already have an isolation switch (a) before the current sensor (b) would it make sense to add one? Would it also make sense to add one after the Henley blocks for each CU to be able to isolate them independently or is this overkill and unnecessary expense?

Can I set up all 6 batteries in one bank or should they be in two banks, and depending on which , what gauge of cable do I need (f) and what isolating switches do I need (g) ?

With Victron equipment and Pylontech batteries, before connecting, do I also need to precharge the capacitors in the Multiplus with a resistor to initially charge them before connecting to the batteries?

I was looking at some 405w solar panels and have room for about 10 and was planning a series setup with a Victron MPPT, what voltage/amp of isolator (i) do I need? And what gauge of cables (h) do I need? between solar panels and MPPT (i) ? and MPPT and Lynx ditributor/Multiplus (h)? Do I need an isolator in both location?

I understand there are a lot of questions here so any help and/or links to resources is much appreciated.


solar system layout.png

dr-mobeus asked
sharpener answered ·

8 Answers

VictronMultiPlus-II 48/5000/70 Adding Generator to Charge the Battery

I have a stand alone system with this Inverter and solar battery system using Outback MX89 MPPT Chargers and 32KVA LiFePO4 battery.
I had my electrician connect the my 7.5KVA generator to AC 1 in to allow it to be used in extended overcast conditions to recharge the battery and take most of the load in those conditions.
On starting the generator, it had an output of 260VAC and the inverter indicators Mains on and Bulk charging came on, then went off. I tried adding load to the generator output to help drop the output voltage (in case that was the cause of the lack of charging), but nothing helped . The generator will carry the load of 3 kettles at once, but the inverter does not like to connect to it.
Are there settings I can change to help it accept the generator power?
What do I need to connect my notebook PC to the Inverter?

tony-from-west-oz asked
JohnC answered ·

1 Answer

Cerrnss Chinese battery being mistaken for pylon in settings


I have got a Chinese brand (Cerrnss) 200ah 16s 48v battery that will not fully charge as it has been mistaken for a pylontech battery and is using the hard coded settings. Please read below for full explanation, any help would be very much appreciated, thanks.

I can't completely explain why, but the batteries are only being charged to 52.4V

The BMS is calling for 57.0V and so the CVL is 57.0V, the absorb voltage in the Multi RS is set to 56.8V, but it only ever gets to 52.4V




Curiously this is the voltage that Pylon batteries are charged to since they have their own voltage specified in the firmware of the GX, when a Pylon battery is detected.

I wonder if your battery is being mistaken for a Pylon or similar 15S lithium battery, and is therefore having a restricted CVL limit being applied, despite the BMS calling for a higher one.


As I wrote that, I thought to look into the details of the DAWES BATTERY, and saw this:


So that confirms my suspicions!!

The firmware in the GX is mistaking your battery for a Pylon and so it is implementing it's hardcoded voltage limit of 52.4V

I think the best solution for this is to raise a question on the Victron Community forum, or one of the facebook groups, tagging a Victron employee, as it would mean a bug in the FW is mistaking the battery for a Pylon. Perhaps there is a way to force the GX to not think it is a Pylon battery, but that is out of my area of knowledge, I'm afraid.

Keen to hear how you get on though...

dic asked
nickdb commented ·

2 Answers

Inverter mini power cut / power loss for seconds / Ups not working

Good day,

I have a 25kva Generator running a 10kva Multipluss II with 10kwh of battery capacity.

the system has been running ok unto Christmas, (4 weeks)

I have tried to replicate it by starting and stopping the generator and under different loads,

however it seems to happen without any 'Trigger'

I have attached the Excel file showing when the power blip happens i have a loss of data on the Logging on VRM Download.

the generator is used to power the home and when the builders come in the site as well,

however it is only connected via a 32a plug, (and its been working with a current limit of 30a set)

i have the issue sometimes were the ac input is not accepted, even when it is at 52hz and at 233v, however i have linked this to when i do a ve config upload, i have to re-set the ve bus to not have this issue.

batteries are bms connected to the cerbo, and they don't have any issues i can see, I have tried to run the system without the bms connected as well. and have no issues except the 15s power blip, which is still random,

any help would be appreciated, (the attached is all i have been able to get to prove it happens, prior to this I didn't really know if I believed the client)

time today 08.01.23@ 15.41

gen snip 1.PNG

gen snip 2.PNG

gen snip 3.PNG

gen snip 4.PNG

Matthew Deal asked
nickdb commented ·

2 Answers

Installed VE.Bus Smart Dongle but Multiplus does not show up

I have a Raspberry PI setup that runs Venus OS and connects to my Ruuvi sensors and MPPT charge controllers (via Bluetooth and, respectively). I have a MultiPlus 12/3000/120-50 120V that I want to connect to the system so I bought a Victron VE.Bus Smart Dongle.

I just ran a standard UTP RJ45 from my engine room where the MultiPlus is located and connected the ethernet cable to the Dongle and the Dongle to the battery bank directly. The Victron Connect app on my phone allowed me to add the device to the network as a Smart Dongle but the Inverter doesn't show up in the system. VRM online doesn't show any devices. Venus.local doesn't show the device.

One other note: Firmware was updated from 1.07 (I think) to 1.13. I am transmitting battery voltage and temperature.

I was under the impression that I would use the Smart Dongle to see and control the inverter. Please let me know what I need to do to make that happen. Thank you.

sailorzach asked
sailorzach answered ·

1 Answer

Mutiplus won't charge after low voltage warning

I've got a Multiplus 24/3000/70. The batteries went too low and the low voltage warning is blinking. I'm plugged into shore power and it should be charging the battery or at least passthrough. Right now, the lights and power kick on for a second every minute and then go back off. Please help! I am totally dead in the water with dead batteries that won't charge back up. If they would I'd be fine.

Now the overload and low battery lights are both blinking. I've disconnected all loads.

I've already tried turning it off and on again lol


joshestes asked
nickdb answered ·

1 Answer

System dead, please advise

Hello all.

So just returned from holiday in the mountains and checked my setup, looks pretty dead to me.
On VRM Portal zero info since early December, says “No Data to display”, which seems odd coz I remember checking in before I left. Nevertheless, here’s what I can see, visually:

Inverter lights: Charger / Alarm
MPPT lights: Float
Cerbo GX: nothing.
Pylontech: Run light, single slow blink. No SOC lights.

I don’t even know what to think or do.
Where do I start?

Thank you.

rattus asked
gazza answered ·

4 Answers

How looks the Puk code?

On my solar panel are two stickers with codes. One with 18 numbers and one with "SPM" + 9 numbers..Witch one is the Puk code?

theo-vernimmen asked
theo-vernimmen answered ·

2 Answers

Victron 160AH Lead carbon batteries

Hi I've seemed to have lost a lot of capacity in my battery bank 8x 160 AH Victron lead carbon, they were new in mid 2019 so just over 3 years old, the BMV has recorded 104 charge cycles and 507 full charges ( sync to 100,%) our average discharge is 107ah, we now get a low voltage warning around 80ah, basically we have to run the generator in the evening to get something like 90% change if the solar hasn't got it above 90% or we end up with low battery warning in the morning or shutdown with voltage about 38 volts, the battery settings are hopefully in the picture below with the history page.

I've spoken to my dealer he's essentially said out of warranty and buy new lithium! I'm off grid so totally dependent on the battery bank, I've checked and cleaned all the terminals my next option is possibly removing 4 of the pack and getting them tested and charged with mains power to see if they are still usable, interested to know if this is normal for 3 year old batteries or if something is setup incorrectly?


Martin asked
kevgermany commented ·

3 Answers

How do you advise Victron that the Webinar subtitles are embarrassing?

Just sat through the webinar "

Victron VRM Update Webinar 2022

Had to laugh at the subtitles which might be a tad embarrassing


Michael Ziegler asked
Michael Ziegler commented ·

3 Answers

Recorded VRM seminar

I was not able to take part of the whole seminar yesterday. Where can I find the recorded version of the ""Walkthrough of recent VRM and Venus OS features"?

paros asked
klim8skeptic commented ·

1 Answer

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