question

Andrew avatar image
Andrew asked

ESS keeps cycling batteries during daytime

Multiplus II 48/3000/35-32

Bluesolar Charger MPPT 150/35 rev2

Vinus GX Controller

150Ah Gel Navada


I am having issues where ESS with Optimised with Batterylife or Without Battery Life. It will discharge the batteries to my SOC of 80%, start charging the batteries to 100% again but in the time that it charges the batteries the MPPT will only charge the Batteries and not feed any excess solar to loads.

Also how do I set ESS up that it will only use Battery power at times of low solar, ie. at night and then only recharge batteries when solar is available again

ESS
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3 Answers
Andrew avatar image
Andrew answered ·

2kWp installed, 2x 4 250Wp Panels

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Rob Fijn avatar image
Rob Fijn answered ·

Hello @Energyvest, by default it should do what you expect from it.. You only set if you Feet-In excess solarpower and you need to set Minimum SOC (Unless Grid Fails).

The question is: You say it discharge the battery during the day. I would assume your load is too big in compare to your harvested solar energy. Your Mulit will use the battery as long as this is above the SOC set point... Your Solar can not keep up, as the mulit 'takes' more..

What do you think?

Regards, Rob


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Andrew avatar image Andrew commented ·

Hi Rob


I would have expected it to use PV and supplement the shortfall then from the Grid.


Also what my problem is that when recharging the batteries from PV after reaching the 80% SOC it does not feed the excess Solar to the loads and drops the the solar only to what the batteries require.

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sinbad avatar image sinbad Andrew commented ·

ESS will use PV and supplement with battery until you get down to the min SOC. At that point it will then use grid for loads, and divert all PV to charging, until you're back up to min SOC + 5%, at which point it will drop grid to the target point, and run loads off PV with battery supplementation... and then repeat the cycle.

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Rob Fijn avatar image Rob Fijn commented ·

Hello @Energyvest, You say that the MPPT output drops.. This should not be. First of all when you login to the MPPT via VictronConnect (via Bluethooth) you must read ESS at "State". What do you read here? (VictronConnected>STATUS > then look down at Battery when you see Voltage, Current and then "STATE")
This should read ESS, as you must have the ESS assistant in your multi.

You do have the latest firmware in your MPPT, Multi and Venus?

Regards, Rob

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Andrew avatar image Andrew Rob Fijn commented ·

The Firmware is up to date on all three devices.

Venus GX v2.52,

Blue Solar v1.47,

Multiplus II 470


The MPPT "State" says External Control not ESS

ESS assistant is installed on Multi

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Rob Fijn avatar image Rob Fijn Andrew commented ·

Hello @Energyvest, in my venus, in the menu of the MPPT, I also read STATE "External Control".

As you have a Venus with no display easy to so. You should look at the VRM app and look at the AC load and then at the same time look at the PV Charger and Grid. Then try to understand where the energy for the AC load is coming from.

In you case you want enough PV Charger to give energy back to the battery and at the same time give to the AC loads...

I hope this all helps you to find where you are short.

Regards, Rob

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Andrew avatar image Andrew Rob Fijn commented ·

This is when set to optimised with batterylife. The day before i had it on Keep batteries charged and it was charging batteries and feeding excess solar to loads and when I switched it to Optimised w batterylife it seemed to be doing the right thing. Charging batteries and feeding excess to loads. But today this is what it did again. Graph shows how the batteries start charging once SOC of 95% is reached and starts charging the batteries ONLY with solar.

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denzel avatar image
denzel answered ·

HI,

I have a very similar setup. I also noticed when using ESS for me it was not efficient, I wanted to use solar first then batteries then grid. ESS never did this on any occasion high or low load demand. I moved to HUB-1 PV. My system now users Solar to keep batteries charged and feed the loads.

In the Event the load demand is greater than the solar it users the Grid.


Regards

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