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multiplus in parallel

Multiplus and power supply in parallel


I have a 12v 800Ah LFP battery bank I charge shore power with a multiplus 12/3000 on board my boat. I want to increase the charging capacity with with an extra shore connection. The natural choice would be to buy an extra multiplus, but these are not exactly cheap. So here's my question ... can I use a 100-150A power supply in parallel with my multiplus up to eg 70-90% SOC and top up to 100% using only the multiplus? Good or a really bad idea?

matsy asked
wkirby answered ·

1 Answer

Error communication between 2 Multiplus 24-3000

Good morning to everybody,

I'm working actually on a boat with several Victron products. this boat have 2 multiplus Victron 24V3000VA. they was supposed to be connected together but it never worked.

I tried to connect the 2 multiplus 24V 3000. the both are working fine in stand alone. the both are communicating with my computer when there is only one connected. I also have a blue power panel on this installation. one of the multiplus is working fine when connected to the blue power, the other one is flashing as soon as the blue panel is connected.

When I connect the both multiplus together, they are both flashing waiting for the computer to define the master and the slave, but the computer can't connect (first message "target found, receiving supported functions" then, after few seconds, "error during communication").

I suspect a different firmware into the both units. I tried VictronConnect but the firmware is maybe too old and I don't have any communication with one or with the other one (I tried separately).

I would like to upgrade the firmware on both units to have the same version.

The actual version seems to be 2.73 on the one which is working, for the other one, I couldn't find it. (I didn't find the way to get the firmware version from VE-Config).

I can use VE flash to upgrade the firmware but I don't know where I can download safely the last compatible version of firmware.

The version on the EPROM are respectively:

261258.VFD (this one seems to be working fine with the blue panel)

2612413.VFD (I think this one may have a compatibility issue)

I have pictures and video of the problem, if that's help... just ask.

Thank you for your help.

michelr asked
Matthias Lange - DE answered ·

4 Answers

Parallel Multiplus Lynx Distributor. How To Fuse?

Hello Victron Community and Happy New Year,

I am thinking of updating my Victron setup and adding a second multiplus. At the moment I have a Multiplus 12/3000/120-50 on my system and I am looking at getting an identical one to increase the power so I can run more ac devices. The battery bank is a 12v 702Ah, that contains 16 Lifepo4 Cells. I might be adding an extra 4-8 cells to it in the future.

I am thinking of connecting my battery to a Lynx Distributor and from there connecting the 2 Multiplus and other loads/chargers on my system. Cable lengths will be kept to the minimum and should not exceed 1 meter (battery to lynx and lynx to each Multiplus).

My concern is that as mentioned on the Multiplus manual, the device has to be fused by a Class T fuse and the Lynx is using Mega fuses. I have seen multiple installation where a Class T fuse has not been used, but I am concerned on not following the recommended way.

The next problem I am facing is cable sizing. 2 x 400A = 800A. I need a cable that is large than 120mm2 or 4/0AWG, which is super hard to find and a lot harder to work with.

Has anyone managed to find a solution using a Lynx Distribution system? The system can take the load as it is rated at 1000A, but it cannot take Class T fuses.

I was thinking of adding an 600-800A fuse on the battery side and the connecting to the Lynx Distribution. An alternative could be two cables, each fused with 400A Class T fuse. But then having more fuses on the lynx will increase resistance.

Any ideas or recommendations are welcome.

I am attaching the diagram of my current system for reference.

Pavan Guru DC Electrical Diagram.pdf

Pantelis Zirinis asked
brucevanderbilt edited ·

2 Answers

Single Phase Multiplus in Parallel. Can I setup with Cerbo GX

Hello Victron Community and Happy New Year,

I am thinking of updating my Victron setup and adding a second multiplus. At the moment I have a Multiplus 12/3000/120-50 on my system and I am looking at getting an identical one to increase the power so I can run more ac devices. Among other components the system has a Cerbo GX with a touch screen.

So far I have been using VRM website to upload the settings to my single multiplus. Can I setup the second one using the same method or I need some kind of connection with my computer or ideally my phone?

I am saying ideally my phone as I have a MacBook and to make changes on the multiplus now I am running Microsoft Windows on UTM and USB support might be tricky.

Pantelis Zirinis asked
seb71 answered ·

3 Answers

Multiple Multiplus in parallel connection

I have one Multiplus 24/3000/70-16 on my boat and want to install another one and configure to work in parallel. The problem that I found yesterday that I bought 24/3000/70-50 (50A max AC current). Will they still be able to work in parallel?

Many thanks in advance.

rostislav asked
Alexandra edited ·

1 Answer

Victron Technician in the Lower Keys Key West

I am dangerous when it comes to electricity . Does anyone know a really good tech in Key West or the Lower keys to help me sort out some problems . THANK YOU Alterboy

alterboy asked
Matthias Lange - DE answered ·

1 Answer

Quattros in Parallel Grid Feeback & Genset connection

Hi team. I recently installed a by 20kva(10kva*2) parallelled quatrro coupled with 2* 20/16 LiFePO4 Freedomwon batteries, 2*150/100 Smartsolar MPPT sitting on 9.75kWp solar. I am convinced i followed all the necessary steps to configure a single phase parallel system. The ACin 1 comes of a changeover switch of utility power and a 3 phase genset.

Problem 1:is now and then it shows negative ac indicating grid feeback which i have not allowed on my ccgx settings. What could be the reason

Problem 2: when the changeover switch is rocked to the genset side, the inverter system takes more than is usually normal to connect to the acIn. When it does connect it makes a repeated humming sound 4 times before disconnecting /rejecting the gen input. It waits for a couple of second and tries reconnecting only to repeat the same sequence again. What could be the case with the gen set ac input?



onwell dzobo asked
onwell dzobo commented ·

1 Answer

2 Multiplus on 3 phase ... Possible?


I need some help, I have a 3 phase installation and just 2 multiplus (My house is loaded mainly on 2 phases anyway).

How can I configure it? Split seems to allow only 3 >Multiplus II? Parallel and then put each Multiplus II on its phase?

Thanks for your responses.


chris-pt asked
Rob Duthie answered ·

1 Answer

Can a new easysolar run parallel with an older multi with new 3000C pylons as on pack without bmv

Easyolar is model 2020 other is about 6 years older single phase system off-grid with 12kw pf1 gen calibrated.

Meiring asked
Paul B answered ·

1 Answer

Final check up of planned off grid installation


I already have some experience with Victron in some RTV (dc only) and with an ongrid ESS installation with a multiplus II GX (on my recent house).

I would like to double check that the following will work:

Landhouse on Mallorca with no grid connection. We will live there all year long.

Planned System:

1x Cerbo GX

2x Multiplus II 48/5000

8x Pylontech 3,5kWh to start with

2x 250/100 MPPT for recharging

1x Generator with 3000 Watts

Some UTP Cables for connection Multiplus / Cerbo GX

2x VE Direct Cables for MPPT

1x BMS Type A cable for Cerbo/Pylontech wiring

1. Should I go with 2x 5000 MultiplusII or 1x 48/10000, especially regarding standby consumption. On top, if the 2x 5000 Multis are not enough I can add another one. This isn’t possible with the 48/1000, right?

Till now I have not configured a parallel system. But I have a MK3 / VE Configure. The house is single phase wired.

My other question is regarding the setup process itself for a parallel system.

2. When I first switch on the multis that are tied together on AC out, aren’t they unsynchronized and will explode? Or do they check if there is Voltage on the output and synchronize even if it is not configured?

3. Or can I just connect them on the DC side, update/configure parallel setup, shut everything down and after that made the final tie up on AC out?

Question about the Generator:

4. I would like to wire it just to an multis AC in as it only deliver continuous 3000 watt. Is that a problem when the second multi doesn’t have it on AC in?

5. Finally, the load:

Water comes from a well, the pump needs about 1kW when running.

Warm water from Solar + backup boiler.

Pool pump needs to run during (summer) day, another 600W.

Standby Consumption of the house should be around 100 W.

On top a kitchen, TV, Laptops, …

I will start with around 14kWp but can add more PV later if necessary.

Will the system fit or is it already to small? From my ongrid house I mostly never see more than 10kW, so I think it should fit.

klandos asked
klandos commented ·

3 Answers

Dual Victron Multiplus, same battery bank, separate AC out.


I need some assistance. I´m installing a setup composed of a battery bank (lithium), 2 smartsolar MPPT, 1 Cerbo GX, two Multiplus II - 48/5000. (240VAC)

The system is installed and it is working fine, but I can´t find a way to only have one inverter/charge working. I understant that when configuring the inverters in split/parallel/three phase, if one shuts down, the other one also turns off.

But one this case, I don´t need to combine the power of both inverters. I have the AC-out´s connected to a swich on the AC switchboard in which we use either one inverter, or the other. So we would like to use the inverters as indepent as possible.

Right now, I have them connected to the Cerbo GX, each with their own VE.BUS cable. I´ve tried chain one VE.BUS cable from one inverter to the other and then to the Cerbo GX, but it is the same, I cannot use one inverter without the other.

Is there any workaround to this? We just want to have more redundancy with the setup, we don´t need to have the combined power of the inverters.

nuno-silva asked
daniyalshah commented ·

2 Answers

Multiplus 48V 3000VA 35AMP - Multiplus AC IN not charging from generator after thunderstorm

I have a standard Off grid solar configuration been running with it for 4 years now. Since the last thunderstorm, my Multiplus is not charging through AC-IN connected to my Diesel Generator but is charging through the battery input.
While my multimeter read 230 on AC-IN VE-Configure read 0V when the Diesel generator is ON.

How should I proceed to investigate further the root of the problem ?
A friend of mine suggested to it might be the relay is KO but i don't know how to test it and if I can replace it.

Thanks in advance!

mrizak asked
mikhail-petukhov answered ·

2 Answers

2 @ Multiplus 2's in parallel seeing incorrect generator input power

We have installed an Off Grid system using 2 @ Multi 2's (5kVA 48v) in parallel on the same single phase for a customer.

All seems to be working well until the generator starts. The system on VRM and CCGX shows the incoming power at a far lower rate than the batteries are being charged at.

This results in the system not being able to correctly calculate how to distribute power when sharing generator power between loads and battery charging. The generator often struggles to deal with the demand going up and down as the Victron system tries to cope.

See an example VRM screenshot to give you a flavour of the issue.

Often, as seen here, the system does not see an AC load at all when the generator is running, though there is. Once the generator is switched off AC loads are shown correctly.

Apologies if this has been covered before, I did have a search on the forum, but nothing popped up.

Thanks.. Chris


offgridsystems asked
Mike Dorsett answered ·

1 Answer

Has it become possible to have a different number of Multiplus per phase?

I have an application that would ideally have extra capacity on one phase as there is occasional temporary extra load on L1.

In June 2019 this was answered as not possible ( @Daniël Boekel (Victron Energy Staff)

Has there been any development on this?


tim-hickman asked
tim-hickman commented ·

1 Answer

Parallelbetrieb mehrerer MultiPlus II (3-Phasen) , verschiedene Leistungsklassen (5000+3000)

Hallo und guten Morgen!

Frage 1:
Kann ich 2 x 3 MultiPlus II verschiedener Größen (3 x 48/5000 + 3 x 48/3000) parallel im 3-Phasenbetrieb betreiben oder müssen das gleiche Leistungsgrößen sein?

Frage 2:

Kann ich 3 Multiplus (3-phase) im einen Raum, mit 3 weiteren MultiPlus (3-phase) im anderen Raum verbinden, wenn die DC-Leitung 8 Meter lang ist? (70-95mm²)

Vielen Dank für Eure Hilfe!

vaiouser asked
vaiouser answered ·

2 Answers

Parallel & 3 phase systems

My current understanding is when parallel or 3 phase connection of Multiplus or Quattro inverters, requires the negative terminals to be connected at all times and can't be broken. ie run through a CB or fuse/disconnector.

Problem is to be compliant in Australia as per AS5139 standards all PCE must have a CB or Fuse/ disconnector on both the negative and positive supplies of each PCE. Note Victron manual indicates in this event to post a sign indicating to home owner on shutting down system to remove communications cable prior to opening CB. All good until the CB operates in anger.

Under my understanding then we can't operate victron's in parallel or 3 phase.????? If anyone has a way around this issue, please comment.


geoffk asked

0 Answers

Pylontech stacks in parallel installed with LV-Hub incorrectly reporting charge / discharge current & limit

System - Single phase - 2x 5kw Multis in parallel.
2x stacks of 5 Pylon US2000 in parallel with LV-Hub
Cerbo GX
It would appear that the LV-Hub doesnt correctly report the correct available charge / discharge current to the GX.

The GX is showing 125A. (which follows the 5x25A mentioned in this doc:

It should report 250A ?

The LV-Hub, also does not correctly report the operating charge / discharge current the the batteries into the system. (Noticed this as we also have a BMV in the system)



Chris asked
Chris answered ·

4 Answers

Multiplus or Quattro in parallel cascade - How do they operate to cover increasing loads?

Just for the sake of clarity... ( i thought i understood this - but as ever the info is grey or not specific)

Multis or Quattros working in parallel for a larger output capacity. (single phase)

Do the paralleled units mirror each other and operate in the same fashion


Is it a cascaded arrangement, where the master is loaded up first, then the second unit starts to come in to cover the load... and so on....?

And then so.....

Shore / generator AC input

Can this be connected to the Master alone , or does it have to connect to each paralleled unit ? (there are schematic examples for both arrangements - ie. two AC sources, but then other information "infers" symetrical connections required.) There is the note about the shore power setting needs dividing by the number of conencted units.



Chris asked
Alexandra commented ·

8 Answers

Search Mode for four Multiplus II in parallel + split phase (2+2 configuration)


I am looking at purchasing four multiplus II 48/3000/35-50 120v to put in a 2+2 configuration -- 2 parallel unites on each phase of a 240v split phase. I'm primarily going this route over a larger 230v Quattro + autotransformer due to the significantly lower zero load draw (52w for 4x mutiplus II vs 110w for a 15kva Quattro).

With low power consumption in mind, I can't find a clear answer to whether or not parallel / split phase muliplus II units can be configured to go into search mode under zero load conditions. This would bring my standby power draw down to 12w which would be excellent.

I know the manuals state AES mode does not work in a non-standalone configuration, but what about Search mode?

yld asked
yld edited ·

2 Answers

Any known issues with firmware 430 on a Multiplus 5kW ?

Two 5kw Multis operating in parrallel - single phase system.

Bench configured and all was well. However, while loading the system up in anger on site, some strange things happen. Master goes into overload and the slave bugs out.

It was looking like they were working together as you woudl expect - i.e. mirroring each other.


When generator is operating - the Multis seem to load it up to around 300w then they trip again on overload.

Cabling is as near as damnit same lengths.

Chris asked
wkirby commented ·

2 Answers

2 x Multiplus 2 48/3000 (parallel on phase 1) in ESS: grid setpoint not reached


I am using 2 x Multiplus 2 48/3000 (parallel on phase 1) in an ESS configuration with a Pylontech Battery US2000b+ (9.6kwh total) and a Venus device with EM24DIN. There also is a Fronius Symo 15-M AC coupled inverter with 10kwp PV connected.

All this in Germany on a 3Phase grid ("Schieflast" is avoided by other measures).

The second Multiplus was only installed yesterday, since then I observe that the grid-setpoint is never reached, there is, especially on battery, always a much greater consumption from the grid than set.

Grid Setpoint is set to 10W, true average consumption from the grid is almost 200W all through the night. As I stated: this is only true since the installation of the second multi.

If I adjust the setpoint to -200W, consumption drops but as soon as the solar kicks in during daytime I am exporting more than I want.

What could be the reason?

Thank you very much!


jfleissner asked
dennis commented ·

1 Answer

48 volt parallel multi not maintaining grid set point

Hello every one.
I’m hoping sone one here can help me with this problem.
I have run a single 48 volt multi plus since 2014. I also have 10 kw of solar panels and 60 kWh battery storage.
every thing has worked very well so far.
I have this week installed a second multi in parallel but I am now having issues with them maintaining the grid set point.
so. To explain what is happening at night when there is no solar power I’m having to set the grid set point to about 220 watts in just to keep them from beginning to export from the batteries to the grid. If I leave the set point where it used to be which was 10 watts draw from the grid they start to export up to around 2 or 300 watts If the house load increases the inaccuracy also goes up and the amount of power exported to the grid from the batteries goes up.
when day break comes and solar energy starts things swap over. Now the units start to import from the grid and the higher the solar energy gets the more the multi’s pull from the grid.
Once I get up to around 7 kw of solar power in having to set the grid set point to around 700 watts export to maintain a reasonable setting close to the desired 0 grid set point.
As evening comes and solar power starts to drop I have to begin to gradually reduce the grid set point again

Does any one have any idea as to what I have done wrong please.

ken357 asked

0 Answers

Parallel Multi

Hi, is it possible to parallel a Multigrid II(processor 2625467) device with a Multiplus II?

masi asked
marekp answered ·

1 Answer

2 Multplus 3000 in parallel w/ CCGX Remote switch On/Off/Charge

Is there any Configuration that I can add a remote switch for on/off/charge only for my two in parallel Multi Plus Inverters with a CCGX?

louisgombkoto asked
JohnC answered ·

3 Answers

Double Consumption on VRM


The VRM is showing double the amount of consumption.

The System comprises of the following

  • 2x - MultiPlus II 48/5000 - Running in Parallel
  • 2x - Smart Solar 250/100
  • BMV
  • Venus
  • 3x - DC-DC 48/24 - For Lighting

The issues that that I have and is best seen between the hrs of Midnight and 6am when the only loads are static. Which you can see on the VRM History. This data adds up individually, but in the System Overview on the Dashboard, the Total Consumption is Doubled.

I’ll try and describe as best as possible below

  1. AC Consumption Doubling/Incorrect Readings
    1. On VRM History between Hrs of 00:00 and 06:00 system shows consumption averaging about 370watts per hour – However –
    2. On VRM Dashboard VRM Consumption showing average of 740watts per hour??
    3. Screen Shots Below of “a” & “b”



sales-1 asked

0 Answers

MultiPlus reported amps under reported when generator running.

I'm running two MulitPlus 24/3000/70-50 120V in parallel. firmware v482.
When the multis inverting the AC-OUT Watts is close enough (+- a few percent) to V*A = W.
With Honda EU2200i generator running:
AC IN: rough average V*(A*1.6) = W
AC OUT: rough average V*(A*2.56) = W

Input limit: 5.0A
Overruled by remote:

Inverter Power Assist: Off

With generator running
AC IN 1:
Voltage: 120
Current: 9.5 (15.2\9.5=1.6)
Power: 1826W
Frequency: 60.3Hz

Voltage: 120
Current: 3.8A (9.725\3.8)=2.56)
Power: 1167W
Frequency: 59.9Hz

Voltage: 26.69V
Current: 22A

As long as I set the Input limit to 1/3 of what I want the maximum watts pulled from the generator, it won't overload the generator. Setting it at 4.3A in general ensures it never pulls much more than 1,800W. At 5W it will creap up towards 1,900W and bounce between there and 2,100W at 120V.

I did measure same length 5' (1.5M) and torque down the 6 AWG(13.3mm2) THHN copper from busbar to the two Multi's the same. However, amp meter shows load is different about 1:3 between the two Multi's. Wondering if that mismatch in load is the cause of my issues? Unsure what to do other than maybe change out the THHN wire to Ancor Marine 266 strand tin coated copper.

Just so strange that the AC OUT L1 current is so far off when in passthru vs. inverting.

Thanks in advance for any ideas.

victron asked
victron edited ·

2 Answers

Existing Phoenix inverter, wish to purchase and add a MultiPlus in parallel.

I have an entirely off-grid installation with an existing Phoenix (48V/5000VA) 230V inverter and wish to purchase a MultiPlus (48V/5000VA) 230V inverter/charger to be installed in parallel configuration. The primary goal is redundancy (in case one inverter fails) and to enable charging of the batteries (if needed) from a 3kW generator (continuous 2.5kW capability). A secondary purpose would be to increase the power output capability.

I know there can be compatibility issues that have to be taken into consideration with paralleling.

The original firmware that the Phoenix inverter came with was 2624413. I have updated the Phoenix inverter from v413 to the latest v482 firmware version today, so if the MultiPlus doesn't come with the latest firmware I am more than capable of updating that to the same version.

I would be seriously concerned if a new MultiPlus didn't come with firmware starting with 26 (VE.Bus - new microprocessor, 230VAC) now, but I've cross checked the list of models document and 2624 is listed as "MultiPlus 48/5000/70-100 (+EasySolar)". It is literally the only model on that list that is 70-100 (70-amp battery charging and 100-amp AC transfer capability).

Am I correct in concluding that if I purchase a 2624 (i.e. a MultiPlus 48/5000/70-100) and update the firmware to v482, if needed, then it should be capable of being paralleled with the existing Phoenix inverter?

Second question is, if I was to purchase the MultiPlus and it failed to parallel could I instead fall back on a configuration to feed the AC output from the Phoenix into the AC input of the MultiPlus to increase the output capability?

I already have a changeover switch in the configuration to change the house AC supply from the Phoenix to the generator and could easily reconfigure that output to feed into the AC input of the MultiPlus instead. I'm not sure how the MultiPlus would handle that changeover from the Phoenix to the generator, I suspect it wouldn't too well, and it might get more complicated if the "Dynamic current limiter" setting needed to be enabled for the sake of the generator.

In the worst case scenario, I would feed the Phoenix output into the MultiPlus input and keep the inverters and generator separated by the changeover switch. This would provide the redundancy and increase in power capability. In this case, if I wanted to meet the goal of charging the batteries I would need to purchase a Skylla 48/50 TG Charger, which is practically doubling the cost as it's price isn't much different from the MultiPlus and it'd probably more beneficial to just buy another MultiPlus and just use that purely as a charger (if it can be configured that way). Really don't think I could stretch the budget to handle this.

My preference would be to parallel the Phoenix and feed the generator into the MultiPlus charger, this would eliminate the need for the changeover switch entirely and I think more likely to meet all the goals, but it would also be nice to know that even if I do everything right, there was a fallback position if the paralleling did not go as planned.

Happy to take advice if anyone has a better option to achieve the goals.

william-croft asked
offroadflow answered ·

5 Answers

Can I connect 2 different Multiplus II in parallel mode ?

I have a Multiplus II 48/3000 and I can get a Multiplus II 48/2000. Does they are matching together in parallel mode ?

volkerjuenke asked
volkerjuenke commented ·

1 Answer

Parallel Multi question


Im planning upgrading to a parallel system. 2 multiplus 3000/24/70 (Gen 1) . I can confirm the following:

Both units are identical

Both units have the same firmware

Relevant VE config changes will be done when needed

Connected to the primary unit currently is a 150/70 MPPT and a 24v Battery + Venus GX and BMV.

i understand the DC cables must be of same lengths and gauge (DC bus will be used)

My questions :

Can i bridge the AC input feed to from the Inverter 1 to power inverter 2?

Can i bridge the AC output feed to inverter 1 to power the loads ?

Does AC output 2 still work independent or does it also have to be bridged ?


denzel asked

0 Answers

Parallel MultiPlus-II current sensing

I have an ESS installation with two 48/3000 MultiPlus-II inverters in parallel with grid feed-in disabled. The ESS Grid setpoint is set at 50W, but I experience incrementally higher (up to more that 400W) grid consumption as the Multi’s power output increases. I assume this is due to slight imbalances in the internal current sensors and/or cabling? Can this be resolved with an external current sensor (MultiPlus-II Current Transformer), and will a single sensor connected to the primary Multi and measuring upstream be sufficient? Note: The utility grid meter is sensitive for grid feed-in and disconnect when sensed

cobus-lotter asked

0 Answers


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