ess discharging Image

ess discharging

Is there any way to set up timed battery discharging?

I have a 10KVA Quattro with 3kW DC coupled PV, 10kW AC Coupled PV and 16.8kWh pylontech battery storage. I'm also with Octopus agile here in the UK, so the price for export sometimes goes up to 64ppkWh exported - I want to take advantage of this! I'm after a way to discharge my batteries on demand - preferably using a bit of python to continually monitor the Octopus agile API. Is this timed discharging possible?

jrgilchrist asked
pdonner edited ·

1 Answer

ESS scheduled charge - batteries discharging after reaching SOC target

Re the ESS manual: "If the target state of charge is reached, and it is still within the period of time set, the battery will stop charging but will not discharge (unless there is grid outage)."

This works fine for me if SOC target isn't set, i.e. if I'm charging to 100%. I have Economy 7, the Pylontech batteries charge up after a couple of hours or so, then go into 'Idle' state. However, if I set an SOC target to say 85% (given I'm now getting usable PV) the batteries reach the SOC but don't go into Idle. The fluctuate between idle and discharge. In a stack of 4 Pylon batteries, it varies which battery goes Idle and which discharges. Sometimes all 4 are discharging. End result is that by the end of the E7 cheap rate period the batteries are at around 83%, not the target 85%.

Eventually, if I can find reliable PV yield forecasting data, I'll be controlling charge/discharge/SOC via modbus but wondered if what I'm seeing is 'normal'? Pic below of 'scheduled charge'/no grid outage/discharging.


johnone asked

0 Answers

Victron connect ESS issue

Hi All,

Does anyone know why the remote console screen shows ESS #3 (BMS disabled charge) while on Victron Connect it shows ESS #4 (BMS disabled discharge)?

The inverter remains in passthru until battery cell voltage naturally decays sufficiently.

I understand the requirement to disable charge, but why does it also prevent the ability to discharge?

Thanks in advance.




robster asked
Andy edited ·

6 Answers

ESS don't sustain DC loads / don't recharge more than 5Amp in BatteryLife Mode

In a Tinyhouse we run a 24V ESS (MP-II 24/3000 v500) with Victron Smart Lithium 200Ah incl. Smart Shunt and MPPT's.

As the Tiny have different consumers over 24VDC, the battery gets drained quite a bit on that side. In the winter a DC floor heating is connected as well.
Unfortunately ESS is not sustaining these DC loads if "min. SOC" is reached. Why?
Further if ESS is in "BatteryLife Mode", the charge state / current never change to more than 5Amp (Slow recharge) so the battery will get drained until flat. If ESS is "without Battery LifeMode" it change to max. charge.

If I analyze the ESS state via NodeRed, I can see that ESS is not changing from

6 - Optimized Mode /w BatteryLife: SoC has been below SoC limit for more than 24 hours. Charging the battery (5A)

to what is needed

8 - Optimized Mode /w BatteryLife: recharging, SoC dropped by 5% or more below the minimum SoC

I'm able to set ESS state via NodeRed to (8).

In my eyes ESS should sustain DC loads in the first place. But at least should change to full charge if SOC dropes to mutch and safe the batteries from get drained too flat.



Any ideas? Thanks

Silvio Franceschini asked
Silvio Franceschini edited ·

0 Answers

3-phase ESS unnecessarily feeds the grid when phase loads unbalanced

My ESS system starts feeding the grid from the battery when I put a high load on one of the 3 phases, while the other two phases are almost not loaded. This seems to be a reoccurring problem after a few tests.

Phase compestation is set to "total of all phases". The grid setpoint is set as +10w.

When all 3 phases are sort-of equally loaded, high or low load, this does not happen.

Any ideas what is going on here?

ESS with 3x multi 3K, AC coupled with 10kw Fronius symo (on AC-in, vrm dashboard incorrect due to using external current transformers) , 8x pylontech US2000C

The multi's use 3 external current sensors which are correctly installed with the 5 meter wires.

EDIT: this seems to only happen when the total load is higher than the PV output, and when above 24A (+-5,5kW load on one phase)




michaelvh asked
michaelvh answered ·

4 Answers

Can an ESS invert from PV panels and discharge from batteries at the same time?


Hello. I have a new PV system installed (by a professional) with 20 Shutten Solar panels 410 Wc, a Fronius Symo 8.2-3 (3 phases), a Fronius Smart Meter 65A-3 (for zero injection, that's a long story with my utility provider...), 3 Quattros 48/5000/70, 4 LiFePO4 batteries 25.6V/200Ah, and a back- up generator. System management is through a Cerbo GX 3 and a BMV700.

I am struggling a bit to get the configuration right. One issue I see is that, during the sunny hours, while the ESS decides to discharge from the batteries, it does not allow production from the solar panels (see screen below). This effectively reduces the efficiency of the system, especially when the loads of the house are such that it may take several sunny hours for the discharge to stop at the min. SOC (currently at 75% on Batterylife), leaving me, by the end of the sunny hours, with batteries charged at 85% or so, nor contributing much to the loads overnight. Do I expect too much from my system, or is there a way to get around this issue? Many thanks for your tips!

rick987 asked
johnone commented ·

0 Answers

Grid Lost after adding ESS assistant


I have three phase system running with three Multiplus-II and Pylontech Batteries. I added ESS assistant to all of the Multis. Now Im getting "Grid Alarm: Grid Lost" error all the time.


I tried to find solutions but had no luck. I would like to keep the batteries charged from the grid.

If any other info needed pls tell. Thank you!

crimu asked
crimu edited ·

1 Answer

Décharge et Maintien des batteries en période Hivernale en mode ESS avec Multiplus 2

Bonjour à tous
J'utilise un multiplus 2 en ESS depuis Mars dernier et c'est mon premier Hiver qui arrive.
J'ai une installation photovoltaïque avec des MO et le multiplus ( avec cerbo gx et compteurs ) fonctionne en ESS pour charger les batteries avec le surplus de production et le soir ou en cas de besoin, injecte dans mon réseau à partir des batteries et ce jusqu'au SOC demandé.
J'ai également 2 MPPT Victron de reliés sur les batteries ( 2 petits strings de panneaux récupérés de ma première installation ).
Jusque fin Octobre c'était parfait.
N'ayant en ce moment aucun surplus de production, mes batteries ne se chargent plus chaque jour et ce malgré les 2 MPPT qui je pensais me ramèneraient qq kwh pour charger les batteries, du moins combler la consommation résiduelle du cerbo gx + multiplus.
J'ai un parc de 16,8kWh de batteries pylontech et je perds environ 1% toutes les 10H
Comme précisé dans la documentation du multiplus, dès que le SOC descend de 5% en dessous du SOC de consigne, le multiplus force une recharge pour retrouver le SOC de consigne.
La recharge se déclenche donc n'importe quand ( en heures pleines si je n'ai pas de bol ) et ce malgré des charges programmées actives sur toute la journée pour empêcher la charge ( avec un SOC bien plus bas juste pour que le multiplus ne tape jamais dans les batteries comme indiqué également dans la doc. C'est une petite astuce qui permet de charger avec le surplus et d'éviter que l'ess ne tape dans la batterie même si le SOC est au dessus du SOC de consigne )
J'ai donc le choix de forcer une chargée programmée en heure creuse pour palier à la décharge quotidienne mais j'aurais préféré l'autoriser à décharger plus que les 5% en me disant que dans quelques jours il y aura un peu de soleil et que la batterie se rechargera tranquillement à partir du soleil.
Je perds donc en moyenne 400wh par jour et je trouve que cela fait beaucoup jusque pour le cerbo GX ( qui consomme environ 300ma sous 12V soit et comme la doc le précise environ 5wh . j'en suis loin avec mes 400wh : jour ).
Je loupe peut perte quelque chose mais le maintient des batteries en hiver n'est pas anodin en prenant sur le réseau.
Quel est votre expérience sur le sujet ?
Merci par avance.

s3b asked
s3b edited ·

4 Answers

What load capacity will I have with this solution

Morning everyone. Ive searched for an answer on this for a couple of days but not been able to find anything. Please can anyone tell me what kind of continuous KW discharge rate I can expect using a MultiPlus 2 48/5000/70-50, with my 7.6kw array, and with a 7kw PV inverter ( to handle my 2 strings) and the 5kva MultiPlus2 48/5000/70-50, along with two Pylontech-US5000 batteries (~9kwh), in a "grid parallel" setup, both when the grid is up and also what the continuous discharge rate is when theres a powercut?

During normal operation, when the loads are big and exceed the Multiplus2 capacity then I'm hoping in a grid parallel setup the mains grid will takeover to meet our surplus demand? Our peak loads in our house can reach 5 to 6kw in our house with 11kw max being reached when I did a test with all ovens, heat pump and appliances etc are going at same time, but generally 6kw would be our average peak loads for half an hour or so in evenings. My question is, when the grid is up and running, how much grid power will I be importing with our loads potentially reaching 6kw and what about our absolute max of 11kw or will my proposed solution meet most of those loads (assuming I have plenty of charge in my two batteries)? And the same question when there is a powercut?

What is the actual continuous kW discharge rate I can expect from my solution? And will I have a "power assist" ability where short peak load demands can be met and if so how much kW and for approximately how long, before the grid takes over?

Thank you for any help and info. I really appreciate it.


matth76 asked
matth76 edited ·

2 Answers

How to prefere feed exces PV power to grid instead of charging battery

ESS working well when SOC~100%, feeding all excess power to grid.

But in morning when energy price is high I want to set ESS to feed to grid all excess power even if battery is not charged. How to set ESS mode 2 for this situation?

Tested 1:
/CGwacs/MaxDischargePercentage = 0
/CGwacs/MaxChargePower = 0
/CGwacs/AcPowerSetPoint = -5000
- this works perfect when AC loads are low and there is is excess PV power.
Problem is when AC loads are higher than PV. It takes power from grid instead of battery (obvious because MaxDischargePercentage = 0)

Tested 2:
/CGwacs/MaxChargePower = 0
/CGwacs/AcPowerSetPoint = 0
- no effect. Still charging bettery with excess PV power

Tested 3:
/CGwacs/MaxChargePower = 0
/CGwacs/AcPowerSetPoint = -5000
- also bad. Will discharge battery to grid if there is not enough (5kW) of excess PV power

Any idea how to achive this?
Thank you for any help.

patrik-trestik asked
nickdb answered ·

1 Answer

Does the Victron EV charging station offer beter system integration with a Victron system than a Zappi?

@Lucian Popescu (Victron Energy Staff)

A customer has a challenge in that his Zappi starts charging when his Quattro exports which is fine. However, when export stops, the zappi continues to charge and drains the ESS batteries.

Objective: 1. Have automated charging of the EV using ONLY excess PV during the day, but without constantly swithing on/off when excess PV is very little or fluctuating. 2. Set scheduled charging to charge from off-peak rates.

1. Will a Victron charging station overcome this Zappi problem being integrated with the rest of the Victron system?

2. Can scheduled charging be set in automatic mode?

ejrossouw asked
l81ker commented ·

2 Answers

ESS - ne pas utiliser la batterie pour la consommation sur AC-IN avec compteur ET112


j'ai une installation MULTIPLUS 2 48v/5000 équipée de 2 batteries pylontech US3000C, une installation solaire 3kw avec un onduleur Fronius raccordé sur la sortie AC-OUT 1 et 2kw de panneaux solaires avec MO raccordés en amont sur le AC-IN .

J'ai installé un compteur ET112 sur la tête de réseau pour prendre en compte la production des panneaux en AC-IN pour la recharge de la batterie.

Au niveau des charges électriques, j'ai branché derrière le AC-OUT 1 et AC-OUT2 l'ensemble des équipements que je souhaite être alimenté via la batterie . Et j'ai laissé sur AC-IN quelques charges que je ne souhaite pas utiliser la batterie (ie plaque induction, borne de recharge véhicule électrique) pour éviter de décharger trop rapidement la batterie .

Cependant j'ai remarqué que suite à l'activation de l'ET112, le multiplus intégrer les charges sur le AC-IN au niveau de l'utilisation de la batterie :-(.

Est-il possible au niveau du multiplus ou ESS d'empêcher l'utilisation de la batterie pour les charges sur le AC-IN ? et limiter la decharge uniquement sur les AC-OUT ?

merci pour votre aide


damd22 asked
Thierry Cortassa (Victron Energy Staff) answered ·

3 Answers

ESS : how don't use battery to power the charges on AC-IN?


I have multiplus 2 with battery and et112 on the grid. Currently th battery are used to power the charge on the AC-IN and AC-OUT .is it possible to use the battery power only for the AC-OUT ?




damd22 asked
sharpener answered ·

1 Answer

ESS relay test pending blocks inverter to work

I have a MultiPlus II GX 48/3000/35 with a Pylontech US3000C installed with the latest firmware. Configured including an ESS.

However, the ESS relay test is listed as pending in the Remote Console and therefore blocking the inverter to work. With a system reset the test is shortly listed as completed, but once the ESS starts the test changed to pending again.

The battery is loaded to 100% and is toggling between bulk and absorption state only.

I have reconfigured everything multiple times and also flashed the firmware twice.

Any proposals?

alexwin asked
alexwin answered ·

1 Answer

ESS Charge during day, discharge at night

Hello All,

I have a 48V 5Kw Pytes battery with a Multiplus II 48V 5KVA.

I have a 3phase grid connection with a 3phase SMA grid inverter.

I added the Victron Multiplus II and battery to charge the system during the day and use


the energy at night. I have set up the ESS assistant to charge from 7:00 to 22:00. After that night meter starts and we don't want to use electricity at night. The reason for this is that we overproduce during the day and overconsume at night.

Now the problem is that the batteries don't discharge.


- Do I need to connect the AC out to the grid? I thought AC in-out can go over the same wire.

- Is there something wrong with my ESS config?

nickseghers asked
nickseghers commented ·

2 Answers

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