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gilemon avatar image
gilemon asked

Grid feed in excess power not working anymore in ESS (keep batteries charged) mode

Hi,

After I have replaced my Smart Solar 150/85 with a brand new VE.can rev2 model, the ESS Grid Feed-in option does not work anymore in "keep batteries charged" mode.

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The system is attached to the grid most of the time and I'm using the batteries for UPS application.

Basically when batteries are fully charged, the MPPT does not output any power anymore.

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If I disconnect the grid input momentally and I reconncet it so that the batteries get recharged, I can verify the PV and charger output some power.

screen-shot-2021-01-23-at-35113-pm.png

Also with the old Smart Solar 150/85, this function was working perfectly.

I have no DVCC and this is what's shown on CCGX under SmartSolar MPPT VE.Can 150/85 rev2 > Networked operation tab:

screen-shot-2021-01-23-at-40430-pm.png

So far I tried:

  • Updating CCGX firmware to latest 2.6.
  • Changing battery monitor from BMV-700 to Quattro

but nothing helped. What am I missing?

Let me know if you need more information about the configuration.

ESS
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1 Answer
gilemon avatar image
gilemon answered ·

It has been a month now and I'm still in same situation.

I have tried "Optimize, and set the minimum SOC to 100%" but it is oscillating constantly. When battery is fully charged it starts using inverter (MPPT/solar + batteries) after 5 seconds it recharges the batteries, then after 5 seconds for a moment (1 second) it does not use MPPT anymore. This dance makes the battery balances go crazy. It does not seem healthy to me.

I also tried enabling DVCC (I had to upgrade Multi firmware to v481), without any change.

The only way I found to force using all the solar input, is by cutting the grid input and forcing battery discharge for 10s. After this the solar is used again to charge the battery back. And after it reaches 100% the excess solar it used in the Multi again.

This is quite annoying because I need to constantly monitor the ESS/CCGX and still this leads to a lot of wasted solar energy.

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seb71 avatar image seb71 commented ·

Not sure what is the cause (except maybe the new MPPT, since you say that your system worked perfectly with the previous MPPT), but try "Optimized without BatteryLife" in ESS and set the minimum SOC lower than 100%. For instance 85%. Then see if it works as it should and then go from there.

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gilemon avatar image gilemon seb71 commented ·

Thanks a lot for your advice, but I can't use "Optimized without BatteryLife" in winter. My battery bank (1300Ah AGM Gel) cannot handle the AC load (>5kW) for more than 15 minutes.

Just for better understanding of the issue, following is today's VRM historical data (very sunny and warm).

screen-shot-2021-02-21-at-52359-pm.png

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gilemon avatar image gilemon seb71 commented ·

I found a automatic solution which is really far from optimal with a crontab job on the ccgx.

2 13 * * * dbus -y com.victronenergy.vebus.ttyO1 /Mode SetValue 2
3 13 * * * dbus -y com.victronenergy.vebus.ttyO1 /Mode SetValue 3

This is kind of doing the trick so far, as it's avoiding wasting these few solar KW every days.

But still, I'm sure I'll need to add some more thinking into this as it might become a problem in some situations. An obvious one being, when I need peak current exactly at this time (13:02).


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