Solar First with Multiplus II

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philipl asked Aug 29, '21

Solar First with Multiplus II

I have a setup with 3 X Multiplus II's running in parallel, 450/100 MPPTs, solar panels and pylontech batteries.

The batteries drain to 20% during the night and the solar panels are sized so that at around 2pm in the day the batteries are fully charged again.

What happens in the morning is that for the first two hours or so, the system charges the batteries and uses power from the Grid for the AC loads. This is completely unnecessary, the solar power early in the morning should be used to power the AC loads and not to charge the batteries.

How can I change it so that the solar power first thing in the morning is used to power the AC loads, and not to charge the batteries?

There will be plenty of time later during the day to fully charge the batteries.

Thank you

VRM

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shaneyake answered · Sep 05, 2021 at 05:31 AM

This is correct operation of ESS. There is a 5% hysteresis in the system. This is there to prevent the battery from being constantly cycled in cloudy/ bad irradiance conditions.

If you would like to change this behavior, you can but you will need to do it via NodeRed or some other type of external control. I have a few sites running what I call soft start, where the system will gradually move the loads over to PV as more PV becomes available.

This way battery will be held at minimum SOC and if a cloud blows over the inverter will throttle down to not run off the battery. This happens until minimum SOC+5 and then the system runs normally.

To do this you will need to install the large firmware and setup NodeRed to do ESS control.
This is an advanced feature and will have a decent learning curve.
https://www.victronenergy.com/live/venus-os:large

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Paul Test answered · May 12, 2022 at 06:20 PM

@kevstone122

agree with you :-)

the ess system need some more configurable parameter to work alone and as many users wont.

let's deside the user about AC-Load or battery first at sunrise......

regards

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Modifications Space

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Answer 1 · 2021-08-29T13:28:00Z

checkit answered · Aug 29, 2021 at 01:28 PM

@philipl MPPTs will always charge the batteries first. If you need AC loads to take priority from solar, a grid-tie inverter would be the best solution.

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shaneyake commented · Aug 29, 2021 at 02:12 PM

The all multiplus inverters are Hybrid inverters, this means that they can run as a grid-tie inverter or as an off-grid inverter. Yes, MPPTs are putting power onto the DC bus but that doesn't mean it has to go to the Batteries, it can be used by the inverter straight away.

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checkit shaneyake commented · Aug 29, 2021 at 06:12 PM

I was referring to a grid-tie inverter such as a Fronius or SMA...

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shaneyake checkit commented · Aug 30, 2021 at 12:30 AM

Yes, I understand but why is a grid-tie a better solution when a hybrid inverter can run loads from solar first or even do a soft start so it covers as much of the loads as it can from solar and the rest comes from grid?

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kalito shaneyake commented · May 06, 2022 at 06:07 AM

PV inverter is powered by PV and outputs AC. It ref the grid to operate and needs no batteries.

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Answer 2 · 2021-08-29T13:30:50Z

muddy1 answered · Aug 29, 2021 at 01:30 PM

You need to look at Victron's energy storage info.

https://www.victronenergy.com/search/?q=self+consumption

You will need to install an ESS assistant onto the Multiplus. You may need an energy meter depending on your system setup.

Then set the battery state in the ESS to "self consumption".

The ESS gives you get further options on the Venus controller. Here you can set times for batteries to charge.

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kaycegivens commented · Sep 20, 2021 at 11:52 AM

Thanks for the detailed reply.

slope game

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Answer 3 · 2021-09-01T07:57:56Z

philipl answered · Sep 01, 2021 at 07:57 AM

Hi,

I have not been able to get this to work. The system is already set to self consumption but it stil uses power from the solar panels in the morning to first charge the batteries for an hour or two.

Can someone please give me some specific details on how to try and change this.

Thank you very much.

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Answer 4 · 2021-09-01T08:17:45Z

philipl answered · Sep 01, 2021 at 08:17 AM

I think I have an idea of what it may be. Under settings, ESS, Mode is set to "optimized with battery life"

Minimum SOC and Active SOC was set to 20%, but then after a while the system sets active SOC to 25%. That may be why the system is charging the batteries first thing in the morning. I will now set it to "optimized without battery life" and see if it makes a difference.

The batteries are fully charged every day by around 12 or 1pm, so there shouldn't be any reason to raise the active SOC.

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Answer 5 · 2021-09-02T07:40:22Z

philipl answered · Sep 02, 2021 at 07:40 AM

I changed to optimized without battery life and set SOC to 20%, but again this morning, the first 1.5kwh that was generated by the PV panels went to charge the battery, and at the same time 1.5kwh was pulled from the grid to power the AC loads. So this is still not working.

Does anyone have more details or suggestion on how to program the system so that Solar power is ALWAYS used FIRST to power AC loads, and only then if there is power left to charge the batteries?

Thanks

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Matthias Lange - DE ♦ commented · Sep 02, 2021 at 07:55 AM

At what SOC are the batteries in the morning?

As far as I know if the SOC falls 5% below the set SOC limit (due to self consumption of the components) then recharging the batteries back to the set SOC limit as fast as possible has the highest priority.

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shaneyake Matthias Lange - DE ♦ commented · Sep 05, 2021 at 05:25 AM

If the SOC drops below 5% of the minimum SOC then the inverter will charge from Grid back to minimum SOC.

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Answer 6 · 2021-12-06T06:27:52Z

Alex Rodgers answered · Dec 06, 2021 at 06:27 AM

Have a similar problem, got around it by installing a contactor on the inverter ac supply - controlled via one of the relays - on the MPPT, inverter or CCGX/Venus

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shaneyake commented · Dec 06, 2021 at 04:59 PM

You don't need to do this. The inverter is fully programmable. You can just setup a rules to make this happen. At the very least you can just use an AUX input on the inverter to trigger grid disconnect and the best you would just disable feed-in via Modbus/MQTT or NodeRed

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Answer 7 · 2021-12-06T08:27:52Z

mcmahan-renea answered · Dec 06, 2021 at 08:27 AM

i have the same question like you! snow rider 3d

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Answer 8 · 2021-12-06T17:16:24Z

tnt369 answered · Dec 06, 2021 at 05:16 PM

Is "Scheduled charging" active in the ESS settings (lowest menu item in ESS)? During the period of scheduled charging, the load is supplied from the mains.

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Answer 9 · 2021-12-06T17:18:26Z

Rob Fijn answered · Dec 06, 2021 at 05:18 PM

If you are not using the ESS there is the Virtual Switch you can use to ignore the AC input. You can use the AC input again based on a condition you can set, this can be voltage but also SOC.

Rob

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Answer 10 · 2022-05-01T19:33:26Z

Hello Together!

I totally agree with the problem of Philipl. Also in my opinion this makes no sense, but nobody understand it correct!

The problem is not the SOC Level or this 5% Hysteresis.
It's okay if during the night the Batterie stops at 20% and in the morning it should be charged to 25%...
BUT the Problem is, if the AC Loads are higher then the Solar-energy!
For example:
Solar 2kW, AC Out 4kW.
So the Batterie is charged to 25%, Multiplus switch to inverter mode and the 4kW are comeing from the Batterie. The Grid has in this time nothing to do!
But because of only 2kW Solar Energy, the Batterie will reach again the 20%. Then Inverter Stops again and repeat it. The Full Solar Power will be used to charge the Batterie to 25% and all the 4kW are used now from the Grid...Why??? We reach 25%, after this discharge to 20%, again again again. This makes absolutely no sense! Why i should charge the Batterie, and don't use the energy direct for the house!
I understand the Problem, because at the end of the day this is correct. So System will assist the AC-Out always from the Batterie. For this we have the Batterie. But the start in the morning is an different Situation! We cannot put any energy from Solar to the Batteries, before the Solar is higher then the ACOut.

FIRST must be the AC Output, so the internal LOADS from the House are used from Solar Power. If i have 4kW in the House and 2kW from Solar, i can use 2kW from Solar and 2kW from Grid. 0 Ampere from Batterie. Why we need to charge Battery?
If the Solar Power will reach for example 5kW, then we can use 4kW for house, 1kW for charging!
This means the Start-up procedure during the morning is wrong in my eyes.

I understand it's difficult to descripte and change software but i have 2 ways:
-Maybe can we adjust somehow the 5% Hysteresis? So If we maybe just use 10%, then the SOC Limit need to reach a higher level and batteries have more KWH saved, then we can start to use the Batterie during Solar Power goes down. So we can adapt for each System, depending on their output level!
-Best Idea would be to block charging in a time window. The same like the "planned charging" i want an "planned blocked charging" . If i can just block the charging until 10 o'clock in the morning it will be fine. Or just block charging if Solar Power is not higher then 5kW....If its 4kW, then it should run into the AC Out and not in the Batteries!
This value need to be adjusted to the "Standby-Power" from each house. If the Standby is 1kW, then we never start charging before 1kW Solar Power!

For me is this problem really important. Please take attention!
Best regards
Kevin

Answer 11 · 2022-05-06T06:00:06Z

Manda answered · May 06, 2022 at 06:00 AM

I have Multiplus I (the old one) + pylontech + cerbo : with default settings, loads are always powered in priority, regardless the SOC (thus I set the min SOC to 10%). If PVPow > Load, batteries are charged with the difference, otherwise, the difference is drawn from the batteries. I (manually but this should change soon) connect to grid only on very cloudy-rainy days, and in such a case loads have always the priority. I also manage a 1200W water heater with Nodered (rpi 4) and Tasmota, so that the heater never uses energy from the batteries or from the grid.

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shaneyake commented · May 07, 2022 at 08:58 PM

You are running off-grid most of the time which means that you aren't using ESS.

Disconnecting from grid is not a real solution.

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Manda shaneyake commented · May 08, 2022 at 12:09 PM

but he wants his AC loads to be powered instead of charging batteries in the morning...

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kevstone122 Manda commented · May 09, 2022 at 11:01 PM

Yes correct! In the morning it make no sense, that the batteries are charged before the PV power is not higher then the AC loads! The function must be:

If the SOC minimum is reached and the PV Power is less then AC loads, then do NOT charge the Batteries.
This should be until the SOC minimum level and the 5% Hysterese... So if SOC minimum is 20%, then between 20% and 25% never charge Batterie before the PV load is higher then the AC load! If we have 26% and some cloud is comeing, then of course the batterie get discharged unit 20% again! But to get out of this window we need the rule like above!

Best regards
Kevin

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shaneyake Manda commented · May 09, 2022 at 11:13 PM

Yes, I understand that but disconnecting from grid is not a real solution as it can lead to damage of the inverter and loads with constant cycling. Also doesn't allow for feed back to grid.

@kevstone122 If you really want your setup to work like this just install the large version of the GX firmware.
https://www.victronenergy.com/live/venus-os:large
You can then use NodeRed to control the inverter and have it switch modes from Normally ESS to battery hold mode buy creating a flow.
I can assist with this if needed.

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Manda shaneyake commented · May 10, 2022 at 06:53 AM

I'm lost… my system (PV, and grid if connected) powers the loads at any hour of the day, and it charges the batteries only when PVPower + GridPower (if connected) > LoadPower. Otherwise, it draws energy from the batteries.

It's likely that I misunderstand the initial problem…

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Manda shaneyake commented · May 10, 2022 at 07:02 AM

I failed to download the Venus OS large 5-6 times from the dropbox link… Is there any other link to get it? I already use Nodered and Tasmota to prevent the water heater from being powered by the batteries (for example), but I want to try the Victron nodes for more controls.

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shaneyake Manda commented · May 11, 2022 at 03:07 AM

The other option is to use the the firmware update in the gx, if you set to large and release candidate it should install the large firmware but can be buggy at times.

Yes, having the Victron nodes is awesome, you can do a lot more control over the system.

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Manda shaneyake commented · May 11, 2022 at 07:43 AM

I give up… and bugs are what I need less these times…

But, is it mandatory to have the large OS installed to use the Victron Nodes? When I try to use ones, I get this error message: There are no ve.bus system services available. Please check that a ve.bus system is connected or try a different node.

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shaneyake Manda commented · May 11, 2022 at 04:10 PM

The large firmware which is still in Beta runs without any problems.

The installer which was just added this last update can be a bit buggy but once installed I haven't had any problems.

It is not mandatory to have the large firmware, it just makes the install process super simply. It gets complicated to install everything manually.

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Ivanka Al Amreeki shaneyake commented · Feb 09, 2023 at 06:23 AM

oke thank you

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kevstone122 shaneyake commented · May 12, 2022 at 05:38 PM

Thanks for your answer!

Yes with NodeRed is some idea, but i think this is a basic usage and also a BUG...This should be solved by Victron in the ESS System. The laste day i start heating my pool with the heatpump and now i need more power. For example 11kW in the morning...Batterie is charging with 2-4kW Solar power until 25% and then change to batterie mode with 11kW....Totally useless...Just for a few minutes. Empty again and it will repeat!!

Please can we solve this internal in the cerbo gx or ESS config from Inverters!?

Because i want that the MAIN function should run stand alone, without network, withou NodeRed, without internet and so on! So MQTT i just want to use for display some values in my smart home, but not to regulate the Victron system which is a very good system already. Just this Bug!

Thank you a lot.

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shaneyake kevstone122 commented · May 17, 2022 at 12:37 AM

NodeRed runs internally to the Cerbo so No internet or network or anything else needed.

This isn't really a Bug it is by design, it was the simplest solution, it will probably be updated at some point but doesn't seem to be something Victron is focused on. For now Victron does give you the option to control ESS on your own.

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lucadea1985 shaneyake commented · Jun 12, 2022 at 03:03 PM

I also have your configuration and similar problems. I want to charge the battery with only 20A and with the surplus power the loads so that the fronius injects everything into the network, I do not want to charge the battery with the fronius except in winter, I want the fronius to help only if the loads are higher than 20A battery + loads... For now I'm using ignore ac input to do so, with activation setting over certain loads. It seems to me that it is not possible and so I downloaded venus large node red with which I seem to have understood that you can program any logic but I am not able to do it. can you help me? Thank you very much

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shaneyake lucadea1985 commented · Jun 20, 2022 at 10:07 PM

Have you installed the large version?

What part are you stuck with?

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Answer 12 · 2022-05-17T00:20:27Z

kevstone122 answered · May 17, 2022 at 12:20 AM

So how we can solve this issue? Is there any Bug-Fix planned?

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Answer 13 · 2022-06-11T18:17:58Z

kevstone122 answered · Jun 11, 2022 at 06:17 PM

Do we have any solution?

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Answer 14 · 2023-02-09T02:28:22Z

Pat answered · Feb 09, 2023 at 02:28 AM

Fascinating discussion. Very interesting. I may have problems and not even know it.

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