ESS slowly discharges my battery with Keep Batteries Charged

My system slowly discharges my managed battery over a couple of days even while the Keep Batteries Charged option is selected. Currently it's down to 94% and doesn't seem to stop any time soon. My PV Charger is out of commision (Panel Maintenance) so the only charge source is the Grid - which is fine.



Freedomwon 10/8

SmartSolar 150/35/1.54

ESS/Keep Batteries Charged

No Power Assist or anything strange selected. Pure UPS at this point in time.

Any ideas why it would keep on discharging my battery? At some point I am going to need the capacity for grid failures.


Ingo asked
Ingo commented ·

3 Answers

My Agm Camper life duration

Good evening, this is the story of my Agm battery for cyclic use.

We have been living in a camper for almost 3 years.

The battery is almost exhausted.

I mean, with loads of 2/4 amps it is still good.

But with a load of 15 amperes (C 0.15), it only returns 25/30 ah.

I took a test with the recently purchased victronenergy smartshunt.

Is this normal after just 2 years and 8 months of continuous daily use?

The battery has about 1000 light cycles.

It discharges daily at approximately 12.5 / 12.6v.

He only suffered 3 or 4 deep discharges.

It is always charged at 100% every day, from a 300watt panel with a 30 amper mppt regulator.

The charge is set as follows:

- maximum current phase

- absorption phase of 90 or 120 minutes at 14.5v

- floating phase at 13.7 / 13.8v.

- temperature compensation at -3mV / C / 2V (about -18mV / C)

The working temperature has always been between 15 and 30 degrees. So very good.

The charging parameters are correct right?

On the battery it is written to charge at 14.7 / 14.9v in cyclic use and 13.8v in buffer use.

But my cyclic use is very light, almost a buffer use.

So I decided that 14.9v is too much.

Also I have seen that charging at 14.5v, the tail current is reached at the same time as at 14.9v.

In few words, monitoring the absorbed amps, I noticed that 14.5v equals 14.9v.

So I preferred 14.5v because it generates less gas.

The battery is designed for 1000/1200 discharge cycles (70%).

It actually has less than 1000 cycles at 80% now.

francesco asked
francesco commented ·

6 Answers

Pylontech US2000B and VE.Can MPPT

I currently have 5KVA Multiplus with a 150/70 VE.Can MPPT charge controller using ESS with CCGX.

My current VRLA batteries are in need of replacement and was looking at replacing them with Pylontech US2000B or US3000 batteries. According to this article its not possible

Is this still that case as it its not possible at all or are there limitations?

byrons asked
Henrik answered ·

3 Answers

Pylontech - MPPT Yield Limited

Hi everyone,

This is my first post in the community and our first Victron installation so please excuse me if I miss something.

Before posting, following the Forum guidelines, I looked at these posts but I just could not find the answer to our issue.

We have a DC coupled PV ESS:

  • Quattro 48/3000/35-50/50 120V
  • Smart Solar 250/100 VE Direct
  • 5.4 kW PV Modules (3 strings of 5 x 360 W Modules)
  • 2x Pylontech US2000
  • Cerbo GX
  • System recently installed, setup in VE Config and all firmware uptated to latest version

We have noticed that the PV Yield is limited to around 1200-1300 W, regardless if we have 1 or the 3 strings connected. Currenty there are limited AC loads but while comissioning we tested and increased loads and the PV Yield increased up to 2000 W with the additional loads (~800 W)

We set up everything as per the manual and Pylontech specific instructions.

Looking at the different posts and manual, it looks like the Battery BMS of the battery is limiting the PV output. I looked into the parameters of the battery in VRM (screenshot attached) and it shows CCL is ony 10 A, while DCL is 50 A.

Pylontech Params


MPPT Params


The DCL of 50 A confirms that the system is reading the 2x Pylontech batteries correct? The CCL of 10 A with the 120 Volts ~ i.e. 1200 W would to confirm to me that this is the reason why it's limiting to 1200 W with no loads. The MPPT Charge current param is 50 A. There are no extreme cold conditions, the battery temp range sbetween 14 deg C to around 20 deg C during the day. Should 14 deg C already limit the CCL to only 10 A?

If this is the case, then, my questions are:

  • Why if the battery is fully charged, it limits the PV output. We can feed back to the grid and we have played with it enabled and disabled for testing purposes, however the PV yield is limited to the 1200 W. The plan for the system is to feed back all excess to the grid as a regular grid-tied PV inverter even if there's no load but the 1200 W is currently only 25% of the capacity!
  • Could anyone suggest more trouuleshooting stepts to resolve this issue?

Thank you very much for your support.



juan-sebastian-pfeiffer asked
nickdb edited ·

2 Answers

ESS: Can Pylontech batteries limit inverter output during day when SOC 100% and loads run off solar?

The site has a 7200w solar array.

20 x 360w solar panels

250|100 MPPT


2 x 5kva MultiPlus II inverters in parallel.

3 x US3000 PylonTech (under Victron recommendations)

It is an ESS system. (Optimized with Battery life)

after SOC is 100% , when consumption goes >2500w in the day, the panels don't cover the consumption. Can this be because of the continuous discharge rating of the Pylontech batteries? or is this not the issue?




@Guy Stewart (Victron Community Manager) @Johannes Boonstra (Victron Energy Staff) @mvader (Victron Energy)

Can you help, been struggling to find the solution to this problem.

jond asked
nickdb commented ·

2 Answers

VRM advanced graph showing critical loads over time

I have multiple systems running ESS successfully and I get a great visual picture on the new dashboard and on remote console of what my critical loads are (will work when grid down) and my AC loads - will not work when grid is down. I am not am to see this as a graph over time. I am sure it is possible to show this as a graph if the values can be shown in realtime. Please can you guide me as to where to see this info on the advanced graphs.

Richard Douglas asked
Guy Stewart (Victron Community Manager) commented ·

2 Answers

Can I use a Schneider energy meter in ESS?

can i use Schneider energy meter in ESS Victron system to do the self consumption function in stead of Victron energy meter

ola-ali asked
Rob Duthie answered ·

1 Answer

Ac coupled ess not charging

Have 2 multiplus 2 units in parallel on single phase grid connected. Setup as ESS using ac coupled solar on ac input (1 phase of a split phase turbine). System discharges battery but does not use available power to charge the battery. Victron current sensor used and is now calibrated over 24hours. Using internal grid meter instead of external. Ccgx and both multiplus units running latest software.

paul-ham asked
Rob Duthie answered ·

1 Answer

In an ESS system, what is the difference between Sustain voltage, Optimised and Keep batteries charged.

Good day,

I was wondering what is the actual difference between, " Keeping batteries charged and "optimized with battery life at 100% SOC"?

Also if set to either of the above what will happen to the sustain voltage?


Gerrie asked
Gerrie commented ·

1 Answer

ESS with Fronius, problems with overload and AC2

Following setup : 3 x Multiplus 48/5000 II, 1x MPPT 250/100 , 1x Fronius Symo 12.5 and 2 x BYD 15.4

AC1 out and AC2 out are separated.

AC1 loads sum up to 10kW and AC2 loads sum up to 10kW max

We have been observing 2 problems :

1. Approximately every 7 or 10 days we encounter this problem. During daylight, while Fronius is producing 2-3 kW, and system is working with reasonably low loads under ESS batterylife, suddenly one of the phases gives overload alarm and system shuts down. We ask the household, they say nothing of high power was being drawn that moment.

2. During ESS, now and then AC2 output is disabled, although there is grid on the mains.

Following my observations :

This overload situation or AC2 output disabling never happens when system is in passthru mode.

Overload situation seems to happen while Fronius is producing, could it be that due to sudden clouds, the pv production makes a dip and then the multiplus try to invert that missing power ? which is then too sudden and causes overload ?

AC2 disabling : could it be that during ESS AC1 and AC2 are being regarded as one output and as soon as the total load of AC1 + AC2 goes higher than 15kVA AC2 is being dropped ?

What are your suggestions to debug these problems ?

bulraydin asked
bulraydin commented ·

2 Answers

Deep Cycle Batteries Off-Season Charging

I have two Trojan T105s in my small RV that are charged exclusively with my Victron solar system.

In winter when the RV is not in use, I have been letting the batteries charge as always by solar using the recommended voltages from Trojan.

My concern is whether this is actually good for the batteries - recently I found that S.G. had dropped on all cells to about 1.255 - 1.260, equalization did restore to normal values.

I have read that holding FLA batteries in float is not necessarily good as stratification can occur.

Please give me your thoughts and recommendations on charging (or not) when batteries are not in use.

Options I have been thinking about are:

1) Continue do as I am doing and equalize more frequently

2) Alter the charge regime in my MPPT to something better suited to storage

3) Turn charging off entirely and charge periodically only when necessary

Thank you.

lehrling asked

0 Answers

UK Grid ALoMCP - G59

Updates to the G59 standard require confirmation that ROCOF and VS are not used as a means of protection.

If they are they need disabling. Or may need the settings amending.

(useful brief overview from Comap -

The ENA has a database collating the responses from Manufacturers - and what course of action may or may not be required.

Do any Victron devices use ROCOF or VS loss of mains ?



Chris asked
nigelv answered ·

1 Answer

Standard configuration for ESS meter impossible


I am planing for an AC coupled ESS configuration with grid-tied PV inverters. I have 2 design goals, the ESS storage shall be charged by PV excess power only and the stored energy shall flow into the private loads only (i.e. the ESS Multi shall produce a bit less than private load consumption).

Problem comes into play with the standard ESS configuration, in particular placement of the ESS meter. I made a sketch to describe the problem and an alternative solution approach.

As I have seen from the ESS design guide, the CCGX appears to have only input for one ESS meter, which would not support the alternative solution approach.

Any clue, good idea or advice to make it happen?

BR Donald


Donald Polzin asked
Rob Duthie commented ·

2 Answers


Ich habe mit meinem Energieversorger wegen der 70% Regelung gesprochen. Der sehr nette Ansprechpartner hat gemeint, ich soll mir doch ein Rundsteuerempfänger einbauen, der eh ab 25 kVA jetzt vorgeschrieben ist. Dadurch kann ich die maximal Leistung von 30kVA einspeisen. Bisher wäre auch noch nie runtergeregelt worden.}W

Jetzt habe ich gesehen, dass der TRE einfach 4 Relais Ausgänge hat.


Da ich noch andere Solarwechselrichter habe, würde ich in der 1. Stufe diese einfach per Schütz trennen.

Die Frage ist, kann ich beim Cerbo GX einen Eingang so belegen, dass er dem GX sagt, dass er den Schalter "Übersch. Solarladegerät-Leistung einspeisen" Je nach Eingangszustand Ein oder Aus schalten soll?


Kann man es Alternativ über Mod Bus machen?

Liebe grüße aus der Pfalz

mainframe asked
Matthias Lange - DE edited ·

1 Answer

Priority solar in ess connected to ac, ac2 question

Priority solar in ess but connected to ac what happens to ac2? does it still feed from the grid

theshenks asked
Lyndsay Cotton commented ·

2 Answers

ESS shuts of PV Power in Keep Batteries Charged Mode

I have a Quattor 48/8000, MPPT 150/85, Lithium battery back up, controlled by BMV 700 and CCGX. All components are running the latest firmware as of 19 Jan 2019.

When I select Keep Batteries Charged mode in the ESS settings, all power is supplied by the grid. Solar PV is shut off and not available to supplement charging or the AC loads.


This is not how the system should behave, as per the ESS manual.

When the mode is changed back to Optimised (with BatteryLife) PV is again available and everything works as normal.


I am changing no settings other than the ESS mode.

I am really stumped with this one. Can anyone from Victron give any pointers as to what might be causing this behaviour? Could this be something to do with the settings of the ESS Assistants on the Quattro?

Thanks in advance.

deanodxb asked
seb71 commented ·

2 Answers

Schedule between "keep batteries charged" and "self-consumption" in the ESS program

Good morning. Can someone please suggest me to schedule the change the state between "keep batteries charged" and "self-consumption" in the ESS program? Let me explain better, living in a country on the equator with 12 hours of sunshine and 12 hours of darkness a day all year round, I would like to use self-consumption during the day but switch to "keep the batteries charged at night.

My installation:

Victron Quattro 10KW 48V

Frunius 8.2

10Kw solar pannel

Small battery bank 200Ah (which will later be increased ).

Currently everything works well in "Keep the battery charge", and I'm happy, but during the day I waste a lot of energy coming from the panels, and at the same time I wish the batteries were 100% charged at night.

Kind regards

aldo asked
nickdb edited ·

3 Answers

Quattro - utility and generator + ess

Hi All,

I am installing a small system 16x385w jinko mono + 2 x Smart Solar 250/85 MPPT + 1 x 8kVA Quattro + 2 x Solar MD SS4074 batteries

I would like to install the 8kVA Quattro - with 2 inputs - 1 x utility and 1 x generator, and run ESS, not to feed back into the grid, just to maximise the use of the solar.

The generator will auto start/stop with assistant on quatrro.

i have heard it is better to connect the generator feed to input 1 and utility feed to input 2 - how will this affect the ESS?

Looking for advice on this setup.


Alex Rodgers asked

0 Answers

ESS large battery draw on Scheduled Charge

System details :

  • MultiPlus-II 48/3000
  • Pylontech US2000B Plus 4.8kWh Li-Ion Battery
  • Venus GX
  • ESS

I'm running an ESS system and noticed that the startup of large AC loads are being powered from the battery / inverter when on scheduled charge. The scenario is as follows:

  • Scheduled charge period
  • Target charge has been reached
  • Grid is available
  • Zero PV

Under these conditions, my understanding is that the system should be relying on the grid to power the loads (with minor background losses). What I'm seeing is that the batteries are used to support the startup of large loads while the grid contribution is slowly ramped up over a few seconds. In the screenshot below, we were using a clothes iron that switched on and off frequently. This resulted in large loads being pulled from the battery each time the element switched on and corresponding charges pushed to the battery when the load switched off. Any way to change the behaviour and get the system to rely on the grid in this scenrio?




Here is less extreme example where a kettle is switched on and pulls 14A from the battery during a scheduled charge period:


kempza asked
nickdb commented ·

1 Answer

Multiplus 2 and AC coupled PV Inverter- Behaviour in Grid Failure when Battery is fully Charged

My ESS system shuts down after approx. 10 to 15 seconds when the Grid fails and the Batteries are fully charged. The Multi and the battery was added to a standard grid connected PV system which is 10 years old. The grid configuration setting of the PV inverter has not been changed.

System components

Multiplus II 48/5000/70-50

Colour Control

Carlo Gavazzi ET112 Meter at Grid side

SMA SB5000TL-21 AC coupled on AC OUT 1; Carlo Gavazzi ET112 Meter at output side of PV Inverter

24x2V/500Ah LA Battery Bank

ESS Assistant is configured as below

The Solar Inverter will start reducing its output power at 50.2Hz

Output power will be reduced to minimum when the frequency is 52.7Hz

The Solar Inverter will disconnect when the frequency is higher than 53 Hz

karlheinzhaller asked
karlheinzhaller answered ·

1 Answer

Ladeschlussspannung (end-of-charge voltage) wo einstellen


Mein System besteht aus Pylontech US2000, Multiplus II 3000, MPPT 250/100 und Cerbo GX, alles als ESS konfiguriert und stationär Zuhause installiert.

Wo kann ich die Ladeschlussspannung einstellen/herabsetzten um den Akku zu schonen?

unter device list ---->pylontech batt --->parameters kann ich "CVL, CCL und DCL" sehen aber nicht einstellen.

unter --->settings --->DVCC kann ich " maximum charge current" einstellen aber keine Spannung wann die Ladung beendet werden soll.

Zur zweiten Frage: Ich habe einen kleinen TFT-Monitor an den Cerbo über HDMI angeschlossen um das System zu überwachen. Leider wird das Bild im unteren Bereich abgeschnitten, das Bild "console" mit den Livedaten wird nicht formatfüllend abgebildet. Das Monitorsetup ist unschuldig.


rossix asked
Matthias Lange - DE answered ·

2 Answers

Battery Min voltage shows 0v


This is a system that I have at a cabin. Victron 100/20. With (2) 115ah batteries in parallel. I use the load out to control a couple of lights. And to disconnect, if the battery gets below 12.1v (about 50% battery life). Basically it pulls about (2ah). I had someone stop by and retrieve this data (below), to be sure the system is working correctly. To track consumption along with my yield. However i was supprised to see that the min battery voltage was 0v. I just dont think this is correct. How could this be 0v when the system seems to be working in all other areas. I have yield. I have consumption. I have a battery Max. But no battery min! If there was not consumption. And no battery Max. I could assume that i had blown a fuse. But that is not the case. Does any one have any explanation for the data below?


fumanq asked
Matthias Lange - DE answered ·

1 Answer

ESS using Multiplus II and Fronius, 1-1 rule


I currently have a Fronius primo 5kw inverter with 4kw of solar (2 arrays NW and NE) and am looking to add a victron Multiplus-II GX to provide some storage and redundancy for power outages.

I understand that with 4kw of solar and the inverter being only 3kw I will run into trouble with a grid outage if I have the solar inverter on the output of the multiplus due to the 1-1 rule.

Im wondering if there is any way to reduce the fronius down to 3kw as soon as the grid fails to make this work?

I guess any system would need to be very fast to avoid any inverter shutdown however if the solar inverter was to shut down for a short time then ramp back up slowly to a reduced output this might work?

Any thoughts are very much appreciated.



nzmikec asked
sathr answered ·

3 Answers

Using Victron as Voltage Regulator, How does ESS respond ?

I have many cases, where the customers complain about grid voltage fluctuations. In these place I would like to find a solution to use Victron as a regulator instead of a bigger standart voltage regulator.

Attached an example of a design, which I think should work.

In this design Multiplus No:2 is the main inverter, which supplies the loads.

It is AC and DC coupled and ESS will run on it.

However No:2 will only accept 'AC in' between tight boundaries (e.g. between 210 - 230 V)

Hence if there is voltage fluctuation for a longer time, and no sun, the batteries will go below minimum SOC level. Therefore another Multiplus is needed:

Multiplus No: 1 , this will accept weak AC and charge the batteries, which is enabled by No:2 with a relay signal, closing the relay K1. No2 will open K1 as soon as minimum SOC is reached.

My questions :

1. Do you see any problems with this setup ?

2. How does ESS react on such a case ? It will not know about the Multiplus No:1 but see that the battery voltage is increasing. Probably it will not do anything, as long as the SOC is at minimum ?

awaiting your comments.


bulraydin asked
Kevin Windrem answered ·

2 Answers

ESS system not starting

I made an ESS system with Cerbo GX Quattro ET340 with a PV inverter connected upstream of the Quattro on one channel of the ET340.

The four starts when the grid fails but does not start when the PV inverter stops producing.

I have installed the ESS assistant, disabled the virtual switch and configured CEI-021 as Grid code and LOM type B.

Do I need to configure anything else? Thanks

giorgio asked
giorgio commented ·

1 Answer

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
Alexandra answered ·

1 Answer

Why did my soc rise unexpectedly?

First time i see this, soc rises to 100 %, while no excess solar...what could cause this?


jejochen asked
Paul B answered ·

1 Answer

Fronius Zero-feed-in option / 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 3.02)
  • PV modules all with absolutely identical direction and no shadowing
    11kWp in total: 6kWp on Fronius and 5kWp on MPPT
  • 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) - currently 2.62-beta5
  • Any component with latest firmware as of today


thomasw-1 asked
thomasw-1 commented ·

4 Answers

ESS 3 phase 3 with external control, one phase sometimes ignores setpoint

I might repeat myself but i am scratching my head and the problem is not solved.
My ESS is 3 phase, with Multiplus-II 5000 on firmware 474, Venus on 2.60. I use external control.

Sometimes one of the Multiplus units on one phase apparently decides to ignore the setpoints and starts doing odd things .. with the result being a wild ride between feed-in and consumption.

The situation resolves after some time, but that can take an hour or so. The other multiplus'es follow the instructions without issue.


this is the problematic phase only, SP is setpoint.
The overview of all 3 phases for a longer interval is here:


you can see that normally the inverter follows the instructions well ..

Any advice appreciated.


jacola asked
ondra commented ·

7 Answers

ESS selectivity and circuit breakers

Hi All,

today I had a short circuit in the Critical Loads section on my ESS. All circuit breakers in between grid and the short circuit switched off. Whereas I was expecting that only the circuit breaker of the circuit itself should be switched off.

now I’m searching for some design rules to better design selectivity in case of ESS.

The connection to the grid is made by 25A fuses (3 phase). So to maintain selectivity I have a 3P-16A circuit breaker between the switch board and the Multi’s. I estimated that adding an ESS creates its own energy system but now I realize that under normal circumstances the relais between grid input and Critical Load output is closed. Following the NEN1010 selectivity rules I then have to use 10A circuit breakers to individual circuits. But that means I have to swap my complete household switch board because it now contains 16A circuit breakers which is quite normal in Holland. And it also leaves me in a non preferred situation since 10A is far to low for some off the systems I’m using (dishwasher, etc.).

I have systems on the non-critical side of ESS like EV, heat pump and so on. They have there own 16A circuit breakers.

Perhaps someone can help me with some suggestions to create a save and reliable system? Or is what I described the way to go (using selectivity and see the multi as a intermediate device).

kind regards,


hetslimmehuis asked
seb71 commented ·

1 Answer