ESS Image


MultiPlus-II discharging to grid slows down and even stops (before minumum SoC is reached)

I am discharging to the grid at a rate of up to 35A@48V. But as the voltage of the battery goes down, the discharge rate goes down and eventually stops completely. Here are a few screenshots of the readings on the GX device.

The battery voltage can be between 36.0V (0% SoC) and 50.4V (100% SoC). Battery is approx. 10 kWh @48V (220 Ah).

The minimum SOC (unless grid fails) is set to 10%.

The grid set point is set to -500 W.



As you can see, the battery voltage is 40.5V, so there is energy left in the battery...

I have set dynamic cut-off values to 39.0V (0.005C), 37.5V (0.25C), 36.9V (0.7C) and 36.0V (2C).

Sustain voltage is set to 36.0V (during the first 24 hours) and 39.0V (after 24 hours).

My question has two parts (that are probably related):
1. why does it slow down so much (only 2.4A discharge rate @ 40.5V)
2. why does it stop discharging?

bjorn-n asked
bjorn-n commented ·

1 Answer

ESS soll nicht durchleiten !

hallo, ich bin deutscher,

bitte um hilfe,

habe multiplus2 ess, steht immer auf -durchleiten- die batterien werden nichtgenutzt, was mach ich falsch ? vielen dank

gromheisei asked
gromheisei edited ·

3 Answers

BMZ conundrum

I have 2 BMZ 7 batteries. I would like to add more, but I found out you cannot mix those with BMZ X. So now, I am considering to switch to Pylontech to get more capacity. Does any one have experience with switching like that?

Thank you.

pbilka asked

0 Answers

Multiple BMS on two seperate MultiGX devices

Hi team,

originally I have 16 400ah lifepo4 cells connected to a multiplus 2 Gx 48/5000 with a 250/60 smart solar - the batteries have a batrium BMS fitted which works perfectly.

The whole system is configured in ESS mode to work with my grid tied 11.5kw system with a further 4600w of pv on the smart solar.

I have acquired a further 4x Pylontech US2000 modules that I would love to add in as well. Is it as simple as installing another 48/5000 GX and configuring it as a slave inverter to the original unit configured for ESS?

thanks for your help!

covetingdolphin asked
mvader (Victron Energy) commented ·

1 Answer

Multiplus in ESS mode aansluiten op Belgisch net voor thuisbatterij.


Ik heb thuis een multiplus II GX aangesloten op het Net met een 10Kw lithium batterij.

Alles in mooi aangesloten zoals het in de manual beschreven staat en het systeem werkt ook gewoon perfect, Maar nu is de keuring langs geweest om het systeem te keuren en dat wilde hij niet doen omdat de omvormer in serie was aangesloten met het electriciteitsnet en niet in parallel. (Ik vertelde hem dat dit systeem enkel maar in serie kan worden aangesloten en dat alle meet apparatuur vanbinnen in de multiplus aanwezig is, en dat dit toestel aan alle veiligheids voorzieningen voldoet en gekeurd is door Synergrid belgie)

Kan iemand mij helpen met info of voorbeelden van iemand anders die dit ook zo gedaan heeft thuis, zodat ik dit kan voorleggen aan de keurder? Of heb ik zelf iets over het hoofd gezien?

In bijlage de schets van hoe het is aangesloten:



Met vriendelijke groeten


aaroncloet asked
janvd commented ·

4 Answers

ESS: MPPT does not supply the load together with Grid


We have just finished installation of a Quattro 15KVA, Smartsolar 250/100 with 4KW PV, 400AH lead acid batteries, CCGX.

Set-up should be in ESS and mode: Keep batteries Charged. Load is around 6KW continuous (pump). PV is only 4kW. So our expectation was for the PV to be supplying the load with the grid providing the remaining shortfall. When we tried it, the battery indeed charged the battery. But when the battery reached 100%, the system disconnects the grid and the PV and battery supplies the load by themselves.

We also tried Optimized (w/o Batterylife) mode. But still the same operation: PV and battery supplies the load until it reaches the SOC setpoint. Afterwhich, grid supplies the load and PV exclusively charges the battery. When it reaches 100%, again grid is disconnected by the system and PV and battery supplies the load.

We have updated the firmware of the Quattro and CCGX. But still have to check if the MPPT controller firmware is updated.

DVCC is disabled. Is this the possible reason why it is not working as what we expect for the system to do?

There is no internet connection at the site, so it is quite difficult to troubleshoot with me not there and I am just giving instructions to our installer there.

Hope to hear any suggestions/comments from anyone.


jimv asked
chris-ebsworth commented ·

1 Answer

Warning! Voltage cutoff not working on SmartSolar. Many expensive batteries destroyed.

Hi. I have over 100x SmartSolar 75/15 controllers. I have discovered that when used on a 24v system, even though the jumper is on pins 2+3 (Cutoff should be 23.6v). It does in fact not cut at all. On many of my systems there has been voltage drop all the way down to 17v. I have lost $1000s in destroyed batteries.

Is this a known fault? What can I do about warranty?

I bought them from Access Antenna in Perth, Australia. They have provided no support other than directing me to ask my question here.



Thomas Rasmussen asked
klim8skeptic commented ·

1 Answer

ESS 3phase 80A per phase et340 meter max current or CT's

what to use as an import export meter if main power supply is rated at 80 A per phase. ET340 meter is rated at max 65A per phase. is there a bigger meter there or meter where CT's can be used ? thank you

energy-freedom asked
dean-d commented ·

1 Answer

ESS - 3 Phase system feeding back to grid


I have a 3-phase system consiting out of 3 Mulitplus 2 GX 5kVA inverters, a Cerbo GX, Pylontech batteries and 3 MPPT's.

When Inverters supply non-essential loads on AC Input side, the one inverter (L1) frequently feed power to the grid although I have a similar 1.8kW load on all three phases (3-phase element). The second inverter (L2) also pushes a bit back, but not as bad as L1 and then L3 is perfect. The Grid-meter (EM24) seems OK as when I deplete the batteries and it supplies the same 3 phase from the grid then all is good.

I have set grid feed-in to 0, and minimum set-point to 150W. Any additional items I could check?



I have tried to elaborate in another post, but seems I was just not descriptive enough and not found a solution.

Johan Pool asked

0 Answers

MultiPlus-II grid setpoint without external grid meter

I have a MultiPlus-II that is tied to the AC grid. I recently connected it to a GX (on a Raspberry Pi 3). I already changed the configuration from Virtual Switch to the ESS Assistant. I have no grid metering connected to the GX or to the MultiPlus-II. For the moment, I want to control it manually.

Even though the grid setpoint is set to -800W to feed 800W back into the grid, it doesn't seem to have any effect and the MultiPlus-II stays in Passthru mode.



I have searched this forum and found one similar post ( that ended up to be a bug/singularity.

Mine was cause because of a GX misconfiguration.

See Q4

In ESS, the conditions for the VE.Bus system to be in pass-through (ve.bus state: passthru) are:

  1. When the GX device is no longer receiving data from the grid meter. Note that this is only for systems that are configured to have an external grid meter. See the Settings → ESS → Control without grid-meter setting.

  2. ...

So the solution seems to be simple... Simply adjust the settings.


However, there is no "without grid-meter" option in Settings > ESS > Grid metering


The "without grid-meter" option is in fact the inverter/charger option. This is quite confusing. After setting it to Inverter/Charger, the Grid setpoint works as intended.


So far so good. But as you can see in the last screenshot, the "critical loads" box disappeared.

After I changed the grid metering setting back to external meter, I got the critical loads box back for a short time while it was also feeding energy into the grid.


But then the feed in stopped. Because off course, the setting is wrong. And the register has not been written for 60 seconds.


Correcting the setting feeds energy into the grid again, but then I loose my "critical loads" box again.


I have been switching back and forth a couple of times:

- if I set it to External meter, the critical loads box shows, but grid setpoint does not work

- if I set it to Inverter/Charger, the critical loads box is hidden, but grid setpoint does work.

This looks like a (reproducable) bug in the interface to me. Can someone confirm? Or point out what I'm missing?

P.S.: in case someone notices in the screenshots, I changed the Grid setpoint from -800W to -200W during the troubleshooting.

bjorn-n asked
maciek-haranczyk commented ·

3 Answers

Grid SetPoint and SoC

Hey guys,

Very Quick quesiton. If I set grid setpoint as a -ve to discharge battery when spot price is high, can I rely on the SoC setting to stop discharging when the batteries get too low?

What one takes precidence?


mike-casey asked
mike-casey commented ·

1 Answer

ESS with grid parallel PV Inverter

Dear community, good morning

I have a Multiplus II GX Inverter charger configured with ESS asistant under Optimized mode.

Battery bank 48V 4 x 12V LipoFe Smart Batteries from Victron with VE.BUS-BMS.

The installation has an ET112 grid meter monitoring both Multi and load power.

Grid Set Point is set to 50W to avoid feed in the grid.

Currently I have set Schedule Charging to:

Schedule 1: Everyday Starts at 0:00 / Duration 7:00hs

Schedule 2: Everyday Starts at 7:00 / Duration 11:00hs Stop on SoC 50%

This will charge the batteries during off peak tariff from 0:00 to 7:00 am, Prevent any discharge from 11:00hs to 18:00hs and use all accumulated power during the night.

I am adding a Fronius Primo grid tie inverter with (Fronius Zero feed will be enabled).

I will change my Schedule 1 and add Stop on SoC 70% so I can take advantage of the grid tie inverter to charge the batteries.

My question is how will the system behave since from 11:00hs to 18:00hs Schedule 2 two will be running?. Will it override charge from the grid from Shcedule 2 and charge from the excess in PV Inverter?. I want to take advantage of the solar excess but prevent from charging from the grid during that time.

Thanks for your support.

Best regards,

Javier Moran asked
magpern answered ·

1 Answer

Why does MPPT throttle to zero?

System is running ESS, Victron Multi II 5kVA and 2 x 150/35 MPPTs. The MPPTs throttle down to 5W randomly and for weeks now we have been trying to find a pattern. The only thing I am quite sure of is that it does not seem to happen when the inverter is turned off. In other words, if I allow the battery to discharge and then let the MPPTs charge but leave the inverter off, they work perfectly.

The MPPT (one or the other) will just stop producing and after typically 10 minutes will work fine again. Sometimes it takes much longer like 30 minutes.

I pride myself on being a very good trouble shooter but I must say, this is so seemingly random it is proving to be very difficult to find a pattern or nail down the cause. What I am 99% sure of is that the instruction to throttle comes from ESS and it stops happening when the Multi is turned off.

How can I get access to a Victron resource that can look behind the scenes at the messaging happening between the components to identify the cause of the throttling?

I have three large Victron systems coming up (two 90kVA and another 30kVA) and getting really concerned that we cannot get this issue resolved.

Many thanks for reading!


hannes asked
Michael Timler answered ·

9 Answers

discharge limit battery

Hi, is there a possibility to limit the amount of discharge from the battery (e.g.40A) without limiting the inverterpower from the mppts? I want full invert power when the sun is shining and reduced when the battery provide power. My Multiplus II 48/5000/70 can draw to much power from the batteries. When I limit the Multiplus it is also limiting the inverterpower from the mppts which would not be required. Thanks

skykay asked
Alexandra commented ·

1 Answer

Can multiplus II optimize self consumption of PV AC generated energy in a 3-phase house

Schermafbeelding 2021-01-30 om 12.42.38.png

Wij zijn op zoek om onze zonnepanelen uit te breiden met een batterijsysteem van 20 kWh.
Onze solar installatie heeft 15000 Wp en zal ongeveer 12000 kWh / jaar produceren.
Ons verbruik ligt ongeveer bij 40 kWh per dag verdeeld 50% dagverbruik en 50% nachtverbruik.

We willen volgende functionaliteit :

1. backup en nood systeem in geval het net uitvalt voor een beperkte tijd (max 3à4 uur)
2. een optimalisatie van de eigenproductie voor zelfverbruik en, indien nodig, netvoeding te voorkomen

Kan de Victron Multiplus 48/5000/70-50 ons hierbij helpen en kan de victron in bijgevoegd schema ook aan zelfverbruik optimalisatie doen om het productieoverschot van onze zonneenergie overdag te consumeren s’avonds en s’nachts?

Wordt er rekening gehouden met battery-life voor de winterperiode waar we onvoldoende zelfproductie hebben om de batterij volledig te kunnen opladen? Wat doet de victron in dat geval?

frankvdn asked
bjorn-n commented ·

3 Answers

How do I clear Grid lost but have no grid (never had)

Anyone know why I get this persistent alarm (and the probably related VEbus error 8/11 for the ground relay)

I have no ESS, nor any other assistent working.


josmeijer asked
josmeijer edited ·

3 Answers

What is required in order to maintain the minimum SoC and control the battery discharge at the same time?


1. To have electricity for as long as possible.

2. To use as much renewable energy as possible.


1. To have electricity for as long as possible.

- Load shedding / Unstable Grid

- Cloudy weather

Load shedding after 4am is the worst. Because State of Charge (SoC) is low and it might be cloudy or winter which means PV might only be available later. So SoC shouldn't be set too low in order to reach the first objective, but it can't be too high either in order to reach the second objective.

- High Loads during low SoC

My geyser has a 3000W element and the storage I use is a 7100W capacitor. When the geyser switches on at night then there is sometimes a voltage drop below a critical level and the system faults with a low battery alarm. Grid is then used.



One could set the minimum SoC to 40% and have the grid supply the remaining wattage. This helps, but what happens to the 40%?

2. To use as much renewable energy as possible.

All about how the load and inverter is going to being managed.


During about my first year I was not using ESS and would only switch over to the grid if the SoC was too low, sometimes I had to go fully back onto the grid because the geyser switched on. But ESS helps, although I want to use as little from the grid as possible.

An example:


It is mid day and enough power is stored. I would rather use the stored power than the grid power to make up the balance of what PV cannot provide. .

Another example:


If somebody switches on the stove or toaster and other loads that makes the inverter want to use power from the grid then a/some/all controlled loads should be switched off so that power from the grid is used on the uncontrolled load.

Exploring solutions:

Reference to modes:

Determine minimum SoC:


Mode 3:

Using mode 3 to control the discharge.


Grid setpoint is on 30W, but grid is being used instead of stored energy.

What is required in order to maintain the minimum SoC and control the battery discharge at the same time?


Min SoC = controlled by software

Battery discharge setpoint = controlled by software

Grid Setpoint = maintains the min SoC / supplies what battery + PV can't / outside inverter spec

chrisjan asked
gherlt answered ·

1 Answer

Unstable Grid with ESS

We have a 3-phase ESS system (grid connected) that is giving us grief:

The customer's house is about 2km away from the road, so the grid connection is very unstable and if any significant current is drawn, the voltage drops and lights flicker and other appliances turn off in the house.

The problem seems to be that when the load is large enough for the system to switch over to the grid, the entire system follows the grid voltage, rather than creating a stable voltage from the Multis.

Is there any way to make it so that the AC Out of the system is stable regardless of the AC In?

Thanks in advance

Elliot Morgan asked
seb71 answered ·

1 Answer

Activate ESS Mode 2 not possible - MultiPlus II GX

Hello everybody,

the last two days I tried to set the ESS Mode 2. I read a lot in the FAQ, but nothing I did helped.

I already checked the System name:


But until now I can´t change the ESS Mode:


Thanks all for your help


rene-baars asked
fred48 answered ·

3 Answers

What does ESS Relais Test Relay Test??

Hi all,

My MultiPlus 2 GX is not discharging the batteries. According to the documentation, the ESS Relay Test is not completed. I have checked it in the settings, and indeed it is not done.

Can someone explain me please, what this Test does and how to start it?

If i choos "Ausgleich" the first option on the screenshot, it starts to charge the battery. Not regarding the state of charge not the max. allowes charge voltage. It's set to 56V and I charges even > 58V.

I'am worried, because my battery is 100% charged and discharge is not working at all. Any good idea how I can get this stupid test done?

Kind regards



schnema asked
schnema answered ·

2 Answers

ESS batery usage preference

Hello, Im running 3 phase ESS system with Multiplus II 3000/48 and one Victron MPPT 150/100. I would like to ask if it is somehow possible to force ESS to use as much solar as it is possible and take the rest of the required power from the grid instead of taking it from the battery? It seems quite anoying that when ESS #1 (and in case of batteryLife #2) occurs, ESS turns off the inverters, which prevents direct use of solar until the battery percentage rises a bit, instead of that I would sometimes prefer not to touch battery and use the rest of the required power from the grid. I guess that most of those issues would be solved by means of using grid tied MPPT like fronius, but that seems to be too much of an investment for me now. Any suggestions howe to solve this with my current setup? Thank you for your answers.

smejfi asked
seb71 edited ·

1 Answer

ESS charge pas SOC 78.5% et injecte sur le réseau.

Bonjour mon installation à 3 printemps est fonctionnait parfaitement. Un multiplus II, Venus, bmv 702, ET112, onduleur, batteries. En réseau sur VRM . Les mises à jours sont automatiques. Depuis un certain temps et la depuis les beaux jours ESS ne fait plus la recharge des batteries avec le surplus . Il injecte sur le réseau une fois les consommateurs assuré. Le SOC est réglé sur 50% batterie life était activé . Sans batterie life c'est la même chose . J'ai mis le multi en charger, les batterie charger à 100% le SOC descend à 78.5% mais plus à 50% ? J'ai tenté pas mal de modification mais rien n'a fonctionné .

Une mise à jour auto peut bloquer le système si il y a une modification manuel sur les paramètres à faire ?

Quelqu'un aurait une idée .

Merci de vos retours

Excellente journée.

Hello my installation at 3 spring is working perfectly. A multiplus II, Venus, bmv 702, ET112, inverter, batteries. Networked on VRM. Updates are automatic. For some time now and since the heyday of ESS no longer recharges batteries with the surplus. It injects into the network once consumers are assured. The SOC is set to 50% battery life was activated. Without battery life it is the same. I put the multi on charge, the battery charge to 100% the SOC goes down to 78.5% but more to 50%? I tried a lot of modification but nothing worked.

Can an auto update block the system if there is a manual modification to the parameters?

Someone would have any idea .

Thank you for your feedback

Excellent day.

florian17000 asked

0 Answers

Can I control the AC-Input relay via an aux input?

I have been looking at all the assistants and the Virtual switch but I cannot find what I am looking for.

Is it possible to switch the AC-Input ON and OFF by using the Aux Input? I'm in the UK and only want to take grid power when it is cheap or I need it. The cheap (Octopus Agile) tariff is not a fixed time, so I want to be the one (well, a Pi at least) to control when I can take energy from the grid.

I was planning to use an external contactor to shut down the grid connection, but since there is one in the Quattro it would be nice to use that.

I think I could achieve a similar thing by using ESS and forcing the charge rate to 0 on a signal on the aux input, but it doesn't feel quite the same...

rotortalk asked
shaneyake commented ·

4 Answers

Struggling with the final step.

I am setting up a system with a bmwi3 battery , multiplus ii , mppt 250/60 , mppt 150/100 and a rs450/100 . I was supposed to be doing this with my father in law who is an electrician but COVID has put paid to that for the moment. I have everything up and running the way I want it using the ESS assurant but I’m struggling with the final step of connecting it all to the house due to a lack of understanding.

I’m planning on winter months using a 4 hour cheap rate tariff to charge the battery from grid to complement the solar.

I have a et112 that I think ( correct me if I’m wrong ) needs wiring in between the main incoming fuse and my consumer unit. I’m awaiting a smart meter and isolator before attempting that :)

If correct I think I can work that one out o.k. However, I have some confusion over ac out and ac in. . I’ve read somewhere that ac in is bi-directional so am I simply running a cable from ac in to my supply after the Carlo gavazzi ? Or do I run a cable from ac out to there and a power supply in from my consumer unit ?

many help would be appreciated and if I’ve missed out any necessary information please let me know.

chapelier asked
chapelier commented ·

1 Answer

Charging EV with excess PV when battery full

Looking for a solution: using an ESS system, when homebattery is fully charged, ideally the excess solar power now is used to charge the EV if it is plugged in. Has anyone worked on such project? There are solutions to charge an ev with excess solar, but this doesn't include a battery in the system.

This one can be programmed together with the victron if i am correct, but have litteraly zero experience with this. Any thoughts?

jejochen asked
jejochen commented ·

1 Answer

ESS Not Working - Bulk charging - Not discharging - Overload error - Pyl Bat 99%


I need some help, after 3 days of trying all options I am loosing faith!

I have 2 MultiPlus-II 5KV Parallel (firmware 481), Cerbo GX (firmware 2.63 - coming from 2.58 -2.62), Fronius Primo 6k (working okay), Pylontech 6 x US3000, ESS Installed and configured on both devices. When not in ESS mode all works fine (Inverting, Charging, Passtrough, 'Off-grid', etc). Only when in ESS mode it all goes wrong!

When switched on the Multiplus goes to 'Bulk charge'. Starts to charge batteries and starts fluctuating. Fluctuating from 300 watt to 800 watt in a constant sinus on the Grid side. MP-II's are moaning when power is on it top. MP-II's keep fluctuating and charging for 15 - 40 minutes and than an 'Overload error' (most times on the Slave). Complete reset and it starts over again or the Main Fuse trips and they go in 'Inverter mode'.

Even when batteries are at 99% it's doing this. Have reinstalled and tried all the settings over and over again.


I added the configuration files (remove .TXT ;)

ESS Settings are:




None of the 'Scheduled Charging' options work. ESS does not react to any setting. So now all disabled.


Posted an earlier question (thanks for the help). After new firmware and trying I could pin it down to ESS.

Love to hear what's wrong or what I am doing wrong. Dealer came with the option to send them both back to Victron (he is lost to). Hopefully somebody can have a look before we send them back.


Victron Multi Setting Inc ESS Assistant.vms.txt

robertg66 asked
robertg66 commented ·

2 Answers

Inverter voltage and frequency response on power failure

I have two separate systems where I experience the same problem. Both with Quattro inverters and with a grid-tied solar on the output side of the Victron inverters. In one system it is a Sunnyboy solar inverter and on the other, it is a Fronius. When the grid fails and the system goes into invert mode the solar inverter shuts down momentarily. I think this is because the municipal voltage varies quite a bit and when the grid fails the inverters instantly switch to an output voltage of 230V instead of the 240V that was supplied by the municipality, which will then cause the phase-locked loop in the solar inverter to lose synchronization and shut down. The municipal supply voltage can vary quite a bit, unfortunately, and as such the situation of a difference between the supply voltage and the Victron's voltage cannot be completely eliminated.

My question is this: What is the voltage and frequency output response of the inverters during a grid failure? Does it shift to the set voltage gradually over the course of several seconds or is it instantaneous?

Also, any thoughts on solving the problem of the solar inverter switching off would be greatly appreciated.

nelisvolschenk asked
michelg answered ·

1 Answer

ESS ohne Netzeinspeisung, EM24 benötigt ?

Hallo zusammen, folgendes Problem:

Mein System:



Venus GX

3x Pylontech Batterie

Solarleistung max 2000W

Eingestellt als ESS. Die Software ist aktuell, Update erst durchgeführt.

Da der Energieversorger mir einen neuen Zähler eingebaut hat der nun auch den eingespeisten Strom ins Netz zählt ist mir aufgefallen das der Multiplus2 nach voller Ladung der Akkus und Stromüberschuss ab und zu minimalen Strom ins Netz einspeist, was ich nicht möchte. Ich habe im Multiplus die Netzeinspeisung Aus gestellt. Würde mir ein Energiezähler wie der EM24 hier weiter helfen ? Kommuniziert dieser mit dem Multiplus2 so das absolut kein Strom mehr eingespeist wird ? Oder gibt es eine andere Möglichkeit die Einspeisung zu 100% zu verhindern ?

Vielen Dank für eure Hilfe

heinrich-lindemann asked
Matthias Lange - DE answered ·

1 Answer

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