ESS Image


GX Compatibility with Murata Fortelion


We plan to build an ESS system comprised of a Multi II GX and a couple of IJ1001M Fortelion Murata batteries. These batteries are relatively unknown and we do have first hand experience with them, so we'd have two questions please to Victron tech teams :


- Can you confirm the good functionning of the Murata system with latest Venus OS ?

- Which specific CAN BMS cable should we use ? Type A or B?

We heard that some improvements regarding communication with Murata were made with Venus OS 2.53v. We have been told however that one user experienced communication issues with the GX, we just need to double check before we move forward with that project...

Thanks in advance for the insights !

perma-batteries asked
hkb2020 answered ·

2 Answers

Multiplus II GX enable ESS Mode 3

Hello everybody,

I'm trying to enable ESS Mode 3 with a Multiplus II GX.

In Ve Configure I set the GridCode and configured Inverter/Charger and added the Assistant "ESS".

I've send the settings to the Multiplus.

On the web interface of the CCGX unter Settings -> ESS is just shown "No ESS Assistant found".

Tried reboots and made a fw update to 2.33.

What did I wrong or what did I missed?

Final goal:

Have a "dump" bidirectional inverter for charging / discharging over Modbus like here:

in Mode 3.

snaptec asked
peter-vddriessche commented ·

2 Answers

ESS assistant with two-signal BMS support


I have a problem with the two-signal BMS support in the ESS assistant.
The two-signal BMS support is described very simple and clear in this document:

One signal input is used to allow charging/disable charging and the other input is used to allow discharging/disable discharging.

I selected "Disable charger" on the high-cell/battery full condition. When the BMS activates the input of the Multi, the CCGX shows "ESS #3", which means "BMS disabled charging". But the problem is, that the charger AND the inverter stop working in this case. This doesn't make sense in my opinion, because the battery is full and cannot be discharged, because the inverter is also disabled. So the system locks itself and remains in this state and cannot leave this state.
Then I switched the "Battery full"-input manually and could reproduce this behaviour as long as I wanted: The Multi is in inverter mode and discharging the battery. Then I activate the input and the inverter stops immediately. Then I deactivate the input again and the inverter starts again with discharging the battery.

When I select "Force to float" on the high-cell/battery full condition, the inverter is not affected and not disabled in this case. So this seems to work fine.

The "Battery empty"-input also works fine and only switches off the inverter, whereas the charger is not affected and still works.

I found an entry with the same problem form last year here:
In the first answer from May 27 '19 dunno describes the same problem, which I also observe with the option "Disable charger" on the high-cell/battery full condition, but there is now answer to his question.

Can someone help of the Victron team?

Best regards

tim84 asked
tim84 commented ·

2 Answers

ESS is not selling excess PV to the grid, while it is charing the battery.


Two Quattros 10K-120V- setup in SplitPhase, ACin1 has a generator, ACin2 has the grid

Four MPPT SmartSolar 150/100 controllers with a total of 14 365W panels per string.

Large 1400Ah Lithium Battery managed by Batterie's internal BMS that communicates with Venus via CAN-BUS. The BMS is a REC-BMS.

Venus is configure:


Mode:Optimized without BatteryLife

Grid metering: Inverter/Charger

Multiphase regulation: Total of all phases

Limit inverter per:OFF

Grid setpoint: 0W

Grid Feed-in:

AC-coupled PV:off

DC-coupled PV : ON

Limit system feed-in : ON

Max feed-in: 15000W

Scheduled charging: Disable



1- System will curtail the PV been generated to match the sum of the AC-load plus the BMS requires to charge the battery. When it should produce as much PV as it can and sell to Grid all that is not needed by the BMS to charge the battery.

2-Once the BMS has reached 100% SOC it sends parameter to Venus to charge at 1A, the system does not pay attention to it and send at least 20 to 50A, but now starts to allow the PV to produce the maximum PV and sells to the grid. Any variations in the AC-load make the battery charging amps to spike to up to 100A, at which point the DC Volt also rise to 65VDC. The batteries BMS send a voltage high ALARM and it it happens several times, the BMS goes into protection mode and disconnects the Battery. this also triggers an alarm38 in the Smart Controllers disabling them, and requiring a full disconnect.

Carlo asked
Daniël Boekel (Victron Energy Staff) answered ·

2 Answers

Fronius Zero-feed-in wastes up to 90% of capacity - improvement required

Hi All,

With this documentation I like to demonstrate that Fronius Zero-feed-in algorithm ignores up to 90% of available energy in a zero-feed-configuration, although all produced energy could be fed into battery at that moment.

@Victron&Fronius-Developers: Please read this article and translate improvements into next software releases.

Generic problem description

My PV panel power balance between MPPT-fed and Fronius-fed energy ratio is about 45% vs. 55% (my complete topology is described below). This screenshot demonstrates that this ratio can be also effectively generated and loaded into AC-IN and battery as long as the grid is disconnected from MultiPlus-II.


Only 30 seconds before when grid was still connected, I took that screenshot. You see that MPPT has nearly the same output, but the Fronius delivered only 28% of its actually currently possible capacity. Since the previous screenshot was taken before, it demonstrates clearly that at that moment there was no restriction of the battery taking additional energy (charging limit of 242A current allowed by BYD at that moment of time).


Frist conclusion
Fronius Zero-feed-in feature in Victron ESS wastes plenty energy (>75% in average – up to 90% in peak)

Closer analysis
Following analysis demonstrates that Fronius Zero feed-in mechanism only works as long as you have a steadily deviating power consumption. Otherwise it wastes plenty energy.

1. AC load on AC-OUT consumption is currently low at 249W and Fronius feeds in with 934W only (compared to screenshot in step 3 you see that was is only 50% of the available capacity at that moment).


2. Switch on a mentionable load on AC-OUT1 activates the Fronius within a few seconds to leverage full available capacity.


3. After having switched off the additional load, Fronius continues to produce similar but already slight lower volume. The produced capacity is fed mainly into battery.


4. As long as there is no peak any more on AC-OUT1, Fronius lowers its production steadily down. In that example its returned to 23% of currently available capacity.
Battery SOC was 52%, the currently applied current 52,9A with readiness to take 242A at that moment.


Please improve zero-feed-in feature so that also battery will be effectively loaded with available capacity on Fronius attached PVs.

My environment

· 3xMultiPlus-II 48/5000/70-50 in 3-phase (firmware 477) with a ESS zero feed-in configuration

  • ESS zero feed-in configuration
  • Multiphase regulation on single phase
  • Grid setpoint defined at 80W

· Fronius Symo 6.0-3-M (firmware 3.16.7-1) with 6.030 kWp attached (55% of total PV) – connected to AC-OUT1 (critical loads) – no additional smart meter - sunspec activated

· Victron MPPT VE.can 250/100 rev2 (firmware 1.06) connected via VE-Bus with 5.025kWp attached (45% of total PV)

· PV modules all with absolutely identical direction and no shadowing

· BYD LV 15.4 (allowed charging and discharging current during the test procedure 243A)
BMS connected via CAN-bus (firmware 1.16)

· VenusGX (firmware 2.60)

· Any component with latest firmware as of today


thomasw-1 asked
ossi commented ·

2 Answers

Easysolar II GX - Grid parallel on AC-IN with ESS does it work?

Hi all,

Has anyone managed to do this with an Easysolar II GX and the CT with nothing connected to AC-OUT-1 or AC-OUT-2???

I have an Easysolar II GX set up in grid parallel mode on AC-IN (as pictured below). It is configured with ESS assistant and the Current sensor on my mains (I am using the AS/NZ grid setting). I have other Grid Tie inverters in parallel with AC-IN. Basically using the Easysolar as an AC coupled storage system (store energy in battery when excess solar and use energy from battery when no solar).. The system works perfectly except it keeps failing during the charge cycle typically around 90% SOC. I have also noticed that the GX part of the Easysolar keeps power cycling.

Has anyone experienced this failure? The symptoms are the Multiplus supplies loads perfectly and charges perfectly except when the "GX device" loses visibility of the built in Multiplus (sometimes it also loses the built in MPPT which I am not using and the internet connection). At this time the GX remote console can't see the Multiplus or any ESS configuration so it just turns off and never recovers until I reboot from the remote console OR switch off with 3 position switch on inverter. When rebooted it works again perfectly but rebooting every day once or twice is not practical.

I suspect a fault or firmware issue or memory leak or something wrong with the charging algorithm???

Any ideas or help would be awesome, things I have tried already:

Turned on DVCC, temporarily fixes the issue for 24hrs then goes back to failing on charge cycle

Connected by ethernet not wifi, didn't fix the issue

Set inverter up from scratch again, didn't fix the issue

Did all firmware updates again (with GX device disconnected), didn't fix the issue

This is what I have except nothing connected to the "No break loads". My battery is just AGM with no smart BMS etc.


Thanks in advance


on2itmaclennan asked
Daniël Boekel (Victron Energy Staff) commented ·

2 Answers

ESS system going to passthru several times a day

I updated the ESS assistant in my two phase system recently to the (017A) version which I believe is the current version. Since I did that I have noticed that many times a day the system goes into passthru mode and imports power. See attached pic.

The system has 2 x 48/8000 Quattos running firmware 474. GX device is a Cerbo running 2.60.

I reloaded an older version that was a special assistant derived from the (0177) version which I still had on my laptop and it seems to have resolved the issue.

Is this some kind of bug in the ESS assistant or has something been introduced to make this happen?



mike-lynch asked

0 Answers

My batteries are taking priority over the PV

I have a fronius symo 8.2 connected to the out of the multiplus. The problem is that when lowering the soc of the batteries ( pylontech ) it will lower the output of the pv to 30 w and draw power from the batteries instead of using pv as 1st priority. Can someone help? I can give more info if required.

mihaimicu asked
mihaimicu edited ·

0 Answers

Grid feed-in deactivation not working

Hi All,

I am wondering that ESS feature does not properly respect the deactivated "Grid feed-in" option.
In following screenshots you can see that the grid power flow deviates roughly between -2.000W and +2.000W, although it is not expected to feed-in anything.
Since I am not allowed to feed into the grid, I am forced to move away from ESS to actually deprecated HUB-2 application.

I would highly appreciate, if Victron could consider

  • a HUB-2 equivalent feature in ESS solution again and
  • assure that relevant energy is used mainly from battery and not from grid


  • grid power changing from +1.447W to -1.756W



  • grid power changing from +2.006W to -1.709W




Both configuration options aren't successful.



My environment

  • 3xMultiPlus-II 48/5000/70-50 in 3-phase (firmware 477) with a
    • ESS zero feed-in configuration
    • Multiphase regulation on single phase
    • Grid setpoint defined at 80W
  • Fronius Symo 6.0-3-M (firmware 3.16.7-1) – connected to AC-OUT1 (critical loads) – no additional smart meter - sunspec activated
  • Victron MPPT VE.can 250/100 rev2 (firmware 1.06)
  • PV modules all with absolutely identical direction and no shadowing
  • BYD LV 15.4 (allowed charging and discharging current during the test procedure 243A) - BMS connected via CAN-bus (firmware 1.16)
  • VenusGX (firmware 2.60)
  • Any component with latest firmware as of today


thomasw-1 asked
thomasw-1 edited ·

0 Answers

Modbus address for Maximum charge power in ESS settings


Im currently building an automated battery testing system. When i connect a lithium pack with the VE.Bus BMS and the battery is not allowed to discharge at some point, the multi is going to charge the pack with the power in the "Maximum Charge Power" value. This is not what i want, i want it simply to not discharge anymore.

My question is, is there a modbus addres so i can set "Maximum Charge Power" ess setting right before testing to the right value?

Best regards,


pieter-boomsma asked
warwick commented ·

1 Answer

disparity between DC energy and AC energy in a ESS three phase system, after firmware update






just finished to update the firmware for 3 units Multiplus 5 kW, including assistants by the company who sell entire system:

- 3 x Multiplus 5 kW

- 1 X Fronius Symo 10,3 kW

- Color GX

- 2 x BYD Pro 10 kW each

- Bmw 700

- 36 solar panel, each 300 w/peak

- ESS three phase system, AC coupling

during update, activities was going well, but after it was finished, we clear observe some discrepancy between energy in AC out and energy from DC part, as in the attached pictures.

please note that there is an measurement independent from Victron system.



laurentiupitran asked
laurentiupitran commented ·

3 Answers

ESS mode not transferring to grid when Multiplus 2 5000 is overloaded

I have a site that when the customer uses more than 4000 watts for a period of time that the Multiplus 2 48/5000/70-48 (firmware 477) unit turns off on overload rather than going into grid transfer mode, site is setup up with the ESS assistant (grid connected), colour controller (firmware 2.6) and 14.0kW of BYD batteries. Looking at some other posts it appears that the powerassist is turned off when ESS is active, I thought this was rectified with some of the latest firmware or perhaps I have missed a setting somewhere.


daniel-1 asked
Daniël Boekel (Victron Energy Staff) commented ·

2 Answers

Fronius zero feed-in not working properly

I have read multiple times that ESS is not for off-grid situations but it is not clear to me the reasoning...

If ESS, requires a constant set point consuming from grid, while there are batteries on system to support that load and even tho sometimes it feeds into the grid, I do not see the point of consuming 2+Kwh daily from grid just because of it.

I was thinking, somehow configuring a relay to cut AC-in when battery is over 25% and when it is not off peak hours. That way the system will use ESS when its required, but if not will only use Solar and batteries. Is there a reason why I should not do this?

Currently there is a contactor connected to the Ziehl anti-islanding device, which is NO so I thought, that if I put the contactor trough a programable relay, unless Victron sees its over 25% or its within off-peak times, that relay will be closed, thus not activating ACin.

Is it viable? Is it a crazy idea? If so why?

JSJC asked
JSJC commented ·

1 Answer

ESS System using grid when plenty of Solar available, and Multiplus stuck on float,

I note many have had a similar problem, but all the "remedies offered tried with no improvement"

System is 24V with CCGX , Multiplus 5000VA/24 2 x MPPT Solar chargers, BMV, 12 x OPzV600 Cells, previously connected offgrid, but now with Grid connection,

System updated to latest firmware on all components, and configure with ESS,

Sorry to be a bore with the following but most replies ask for full tech setups to help, !!

Battery capacity set to 600AH, Battery monitor enabled and with SOC Bulk Finished 85%, charge efficiency 0.80

Inverter Output V = 230, DC inputs 21, 24, 22 volts respectively

AES Enabled, (Default)



Charge Curve Adaptive+ Battery safe

Absorb 29.6

Float 26,4

Charge Current 50A,

repeat Absorb 8 hr

ditto interval 7 days

max absorb time 8 hours

Temp comp -32.4

Virtual switch , = Do not use

Assistant ESS ( Energy storage system) with

1 Battery System set to Use OPzS or OPzV batteries

Battery capacity 600AH

Sustain during 24Hours 23.00V

After 24 hours 25.00V

Dynamic Cut off in order, 24,00 V ,, 22,50V ,, 21,10V ,, 20,00V

restart offset 0.60V

No PV inverters

VE Config,

Battery Cap 600AH

Powerassist unchecked

Lithium batteries Unchecked

Dynamic current Limter unchecked

Storage Mode Unchecked,

On CCGX the following has been set under the ESS and DVCC setting

DVCC currently off ( Disabled)


Mode Optimised ( without battery life)

Grid Metering Inverter/Charger

MIN SOC ( Unless grid fails) 70%

Limit charge power disabled

Limit inverter power disables

Grid Set Point 50W

Grid Feed in enabled ( DC coupled PV - Feed in Excess)

Feed-in limiting active, NO


The comms is provided by the VE direct

your thoughts would be greatly appreciated,

mike48t asked
mike48t commented ·

6 Answers

ESS - BatteryLife

Low SOC limit is increased 5% once a day when the battery reaches it for the first time.
Inverting STOPS and power for ac loads is taken from grid.
If then sufficient PV is available it will charge battery.
When the battery reaches 85% SoC on the day, the increment for that day is canceled and the limit remains the same as the previous day.
If the battery reaches 95% on any day, the dynamic discharge limit is lowered by 5%.

ok, i understand when it decrease / increases or do nothing to the low SOC limit.

But what condition ( min SOC level + 3%...5% or what ? ) has to occur that the multi drop grid, START inverting again and power ac loads from battery ?

pete60 asked
ess-and-solar-solutions answered ·

1 Answer

smart net meter communiciation belgium

are there possibilities to connect the ccgx to the new smart meters in belgium, and skip the energymeter?

jejochen asked

0 Answers

What is the difference between ESS mode - Optomized (with BatteryLife) and Optomized (without BatteryLife)

In addition to this it seems that with battery life setting you are able to set when you want your batteries to discharge. How would I go about setting them to discharge between 12am and 6am for x% and then fall back to grid?

andrebotha asked
andrebotha edited ·

1 Answer

Alternative to ET112 100A Single Phase using CT

Hello, I am installing a victron ESS where it is not possible to disconnect the mains live to go through the ET112, is there any other alternative 100A meter with contactless CT recommended and would be compatible with ESS and the CCGX. Thanks

momahmoud asked
betaoil commented ·

3 Answers

ESS assistant charges and discharges the battery continuously when there is not enugh PV, why?

I know that my question pretty much describes what the ESS Assistant should do.

But is there a way to prevent continuous charging and discharging?

My AC loads are mutch higher then what my PV is generating, this is why the ESS Assistant draws current from the battery until my desired SOC is reached but then it swiches of the inverter and is slowly charging the battery with PV and after charging 5% above minimum SOC the inverter turns on and quicky emtys the battery down to minimum SOC. Since my AC load is always greater than what I can generate with PV. It would make much more sense to feed the generated energy directly into the grid to help power AC loads. There is no ecess power, so why always charging 5% of the battery and then quickly emtiy the 5% at maximum current.

I would prefer a constant output power when the AC Loads are higher then what i can get from the PV and then only store excess power in the battery.

Thank you for your Help.

felix-vt asked
layesp answered ·

5 Answers

Help, i need somebody to review my installation diagram.


I'd like to purchase a Multiplus II together with 2 smartsolar chargers. I have a PV array and a battery and a stable Grid connection.

I want to setup the system so that i consume all the energy i can and then either stop feeding back to the grid or feedback to the grid. I am allowed to do this here in Denmark since the multi just got approved here. I would also like to be able to power some things when in rare occasion there is a power outage.

  1. So this means the Multi will feed power on AC IN when it measures there is consumption on the Energy Meter correct ? I mean the Multi gets usage data from the energy meter on 3 phases but itself it can only produce on the phase it's connected, the utility meter will even this out so +1kwh on L1 and -1kwh on L2 gives 0kwh usage.
  2. When LOM is detected it will shutdown on AC IN and produce on AC OUT 1 where i have my loads that i want to keep running from battery, i presume these loads also run while LOM is not detected as i can see the AC IN and AC OUT 1 is connected while there is AC IN correct ?
  3. What is this system called, as far as i can tell this is Grid Parallel with ESS ?
  4. What happens to the loads on AC OUT 1 when i shut off the inverter for maintenance ? They shut off correct ?
  5. Should the AC IN go into a RCCB that makes sure all power produced in the inverter is protected ? I do have a RCCB but now power is produced inside the system and the RCCB won't trip if something happens. Do you agree ?
  6. If i have loads on AC OUT 1 i guess i also need a RCCB there too correct ?

I have spent much time reading and looking on diagrams and came down to this questions which i hope will answer my questions so i can finalize my diagram and get it reviewed. I have attached a drawing how i think the system should be wired. The part that i am most unsure about is the requirements for the RCBO and of-course the questions i have above.



peternielsen asked
warwick answered ·

2 Answers

Victron ESS + ET112 = slow response


Recently I've installed ET112 grid meter on my system (which was using CT sensor previously) and I've noticed that the Multi is very slow on response to load. Currently my system looks like this:


The grid set point is set to -10W. The multi needs a good 15-18 seconds to stabilize after large load kicks in and another approx 15s to stabilize after load drops off. Check the video from VenusGX (the load is switched on at about 16s of the clip and switched of at 43s of the clip):

Is that how it should be? The difference in the load is just about 1.4kW, why is it taking so long to handle that?

Previously I was using CT Sensor extended with Cat5e cable to over 25m long, the system looked like this:


The response to load was pretty much instant. I've recorder video using the same load as on the previous one (load switched on at about 10s and switched off at 23s of the video):

The system need seconds to stabilize

Also you can see a clear difference on the Grid use graph from VRM portal:



As you can see, with CT sensor the system is very close to grid set point, with ET112 grid meter it is way off and hardly ever stay close to set point. The situation is even worst during cloudy day when PV power is fluctuating (you cen see it on my other youtube video).

Is it normal behavior? It looks like Multi can handle this load easily, the problem seems to be in the feedback from the grid meter (or algorithm when ET112 is in use). Is there anything I can do to improve this reaction time??? Please advice.

Kind Regards

mysik asked
rainerb commented ·

11 Answers

Multiplus II and AC Out 2


I am trying to get my head around installation of a Multiplus II. I am installing this in Denmark as there is grid support for this but as far as i understand. The inverter must shut down it's AC Out 1 when the grid fails inorder to protect the technicians on the street to not feed in electricity BUT is there a way i can get power out on AC Out 2 while not delivering to the grid on AC Out 1 in that way i can power some critical things while power is down ? If it is possible i was thinking to put a switch 1, 0, 2 on those critical things so when power drops i can go an d switch it to get power from the inverter AC Out 2 if that's doable and allowed which essentially makes it a off-grid system for that period wile power is down. In the current system i am designing i will have a energy meter and run with ESS since the Multiplus II is a one phase system and the house system is 3 phase so the inverter will start producing energy when it's told from the energy meter there is a usage inorder to get the consumption to 0 as much as possible.


peternielsen asked
harold commented ·

0 Answers

Multiplus charger is turned off via VEconfig but it still charges from the grid?

I'm trying to use ESS "Keep Batteries Charged" mode but want to make sure my Multiplus doesn't use the grid to charge the batteries (i.e always prefer solar).

I've disabled the "charger" from VEconfig and confirmed it is indeed disabled :


However, this has had no effect - the Multiplus still uses its charger to charge the batteries (when there's no sun, which I don't want).

How do I ensure the multi's charger is *really* disabled?


Any ideas?

I have DVCC on (so there's no option to disable inverter charge current unlike when DVCC is off)

My overall setup is..

  • Multiplus 48/3000
  • MPPT 150/70
  • BMV-702
  • 48v 200ah lifepo4 (custom built, third party bms, no connectivity to VEbus) - so ESS is setup with "LifePo4 with other type BMS"

9xsolar asked
9xsolar edited ·

0 Answers

When Charger is disabled ESS does not engage inverter

I have Multiplus in an ESS configuration with PV on input ( grid connected ) and a grid supply to multi ( no MPPT's ) . I'm using 2 wire BMS to control maximum SOC level by disabling charger when I get to say 85% SOC ( via wire from Venus using "Generator Stop / Start " ) . When you get to 85% SOC charger is disabled as desired however should load increase to more than what the PV can supply additional power is drawn from grid and not battery as expected.

I had been using the BMS 2 wire setup previously where you force the charger to FLOAT and it works reasonably well , however the problem is that if you get to say your desired SOC early in the day and you do draw power from the battery - the SOC does not reach the desired SOC by the end of the day due to limited charging capability when in FLOAT mode ( unless you did use suffiicient energy to trigger BULK mode ) .

Is there elegant way to set max a SOC charge state? You can do so with scheduled charging - however it will take power from grid ( ignors PV output ) which is not desireable.

Please can developers implement a proper maximum SOC charge limit

merlepeter asked

0 Answers

Single ESS inverter installed on Phase 1 of a three phase system

Hi All. Hoping someone can assist with an explanation. The Victron ESS documentation says the following:

"When installing a single-phase ESS in a system with a three-phase connection to the utility grid, make sure you install the ESS on phase one, L1."

This is found on the following link:

Would someone be able to explain why it has to be on Phase 1 as opposed to Phases 2 or 3? Thanks.

upszimbabwe asked
Rob Duthie answered ·

1 Answer

Strange DVCC issue, need to disable and re-enable daily to get full MPPT harvest.

Hi guys, wondering if anybody can point me in the right direction on a little MPPT VE.Direct problem.

I have a small Multiplus 24/5000 grid-tied system running great with BMV-700, Venus GX and off-brand DC coupled PV charger with 200Ah of Li-Ion. I've recently added another PV string on an MPPT 100/50 Rev2. Everything has latest firmware as of this post.

The MPPT is working great, except that every day its output is down by a few hundred watts. Heres the wierd part - It comes good when I disable DVCC then imediately re-enable it again. It remains at full output until the next day. Here's a video showing this:

In this video you can observe the output is down from what it should be. After disabling DVCC, the MPPT settles on a much higher output, with most going to the battery (huh? already 100% soc) and a little extra going to the grid. When DVCC is then re-enabled, the MPPT continues to produce full power, and the excess goes correctly to the grid. That is, until the next day.

The utility connection is a 10A circuit, so export is limited by the Multiplus to 2400W. When there is excess solar and the grid circuit hits 10A export, DVCC correctly backs off the MPPT as intended, so the battery is not overcharged past 100% SOC and the 10A grid circuit limit is observed - great.

My suspicion is that there is a bug somewhere in this code which is somehow causing the MPPT to stay backed off even when it should be instructed to return to full power output. When this condition is in effect, the charge voltage target in the MPPT is observed at 27.3V (while battery remains at 27.1V, as observed in the MPPT's menu on the venus GX). The mppt *should* be going flat out, but somehow remains backed off.

No battery current limits are ever being hit, the battery temp is mid 20C at all times, wire gauges are all correctly sized and nothing is getting hot.

Any ideas?

victrowok asked
victrowok answered ·

1 Answer

ESS bug with 0% Minimum SOC ==> discharging not stopped after reaching 0% SOC.

Hi Victron team!

Today I have found the bug in ESS assistant (Venus OS v2.60):

if you set 0% Minimum SOC in BL disabled mode, then system cannot stop discharging batteries after reaching 0% SOC with grid connected.

I waited 20 minutes after SOC reached 0.0%, but system remains in BL disabled mode and did not switch to using the grid (batteries continue to discharge with about 4 A current).

I think, that the ESS assistant in this case expecting -0.1% SOC for stop discharging batteries, but it is not possible. So, exception needed in the ESS assistant for 0% SOC.

(My system: Multiplus Compact 24/2000/50-30 with 2x200 Ah Gel batteries; BlueSolar MPPT 150/35 with 1.2kWp solar panels; BMV-702, Venus OS on RPi. )

VS V asked
VS V commented ·

0 Answers


Hi need some help activating the feed-in limiter dc coupled ,

mppt 150/100 ver 1.54

multiplus 48/5000/70-100 ver 476

color cont. ver 2.6

shentschel asked
shentschel commented ·

1 Answer

ESS ramp too slow for grid compliance

The feed-in ramp of MultiPlus-II 48/5000/50-70 in ESS mode is 400 W/s.

The VDE document "Anschluss und Betrieb von Speichern am Niederspannungsnetz" (available for free) states the following requirement: the regulation error must be below 10% after 3 sec due to a step reponse. The original text from chapter 4.10:

"Auf eine Abweichung auf Grund einer Sprungantwort muss das Gesamtsystem so schnell bzw. genau reagieren, dass der durch den Sprung verursachte Fehler unterhalb der Grenzlinie in Abbildung 1 bleibt und innerhalb von 3 Sekunden unterhalb von 10 % unterhalb des Ausgangswertes liegt."

The document states that this must be tested with the rated current. So, the MultiPlus-II would take more than 10 sec for a ramp of 0W -> 4500W, whereas the requirement is 3 sec.

The ESS manual mentions the ramp's purpose is for stability reasons, but this is contrary to above requirement.

Is this an error in the grid code settings or do I miss something?

fabianwolter asked

0 Answers

Quel CPI pour installation ESS avec un EasySolar II GX ?


J'envisage d'utiliser un EasySolar II GX 3000/48 avec ESS plutot qu'un Imeon pour réaliser une installation en autoconsommation avec sortie secourue de 3kWc, avec deux modules de batterie Pylontech, et avec vente du surplus.

Seulement pour être OK consuel avec un chargeur MPPT 250/70, il faut ajouter un CPI coté photovoltaique, et je n'arrive pas à trouver d'appareils abordables, je n'ai rien trouvé à moins de... 3800€ !!

Avez-vous connaissance d'appareils pouvant faire l'affaire, et chez quel fournisseur ?


yann asked
yann edited ·

6 Answers

667 Posts
597 Users

Topic Experts

Rob Duthie
218 Points
104 Points
Jake Kennedy
10 Points