Can't get IGrid VE II / Sorotec REVO II to use battery if no PV power available

[Itschi]

Hi,

I’m having an issue with an EASun IGrid VE II Hybrid Solar Inverter. My setup is a PV source with 4.2kW and a LiFePO4 battery with 6.7kWh connected as “User Type”. What I’m trying to achieve is as follows:

• If PV is more than sufficient, feed load by PV, PV excess should charge the battery with priority and the remaining power should go to the grid
• If PV is insufficient, feed load from PV & Battery
• If PV is not available (e.g. during the night), feed load from battery
• If neither PV and/or battery is sufficient, use AC (bypass)

Looking at the manual I was thinking of working mode “Solar” with “En PV/AC” enabled would be my choice. It works as long as there is enough PV power available but if PV power goes below load needs, the inverter switches to “AC Bypass” instead of using the battery. Same with working mode “Battery” and “En PV/AC” enabled. As a matter of fact there is no way to get the inverter using the battery as source other than cutting the grid.

Anybody that could give advice how to proceed?

Regards, Itschi

 

[meetyg]

It could be a firmware issue, similar to other inverters: Your battery must be 4v above the low voltage cutoff value, for it to use battery.
I haven't had the time to test it with mine inverter (MUST, not EASUN) but that's what I read around the forums.

 

[Itschi]

It could be a firmware issue, similar to other inverters: Your battery must be 4v above the low voltage cutoff value, for it to use battery.
I haven't had the time to test it with mine inverter (MUST, not EASUN) but that's what I read around the forums.

Thank you for the hint. I checked, but the battery voltage is above cutoff + 4V. After some talks to the support it seems the inverter itself is not able to do what I want. That's why I started to switch the inverter modes using the serial interface with my hone automation. It's not perfect yet, but works.

 

[creon]

Thank you for the hint. I checked, but the battery voltage is above cutoff + 4V. After some talks to the support it seems the inverter itself is not able to do what I want. That's why I started to switch the inverter modes using the serial interface with my hone automation. It's not perfect yet, but works.

How did you change inverter modes with this inverter do you have a link?

 

[meetyg]

Well, it sounds odd that support says it's not possible. I think that your expectations are exactly what these hybrids are for...

My MUST supposedly can do exactly what you expect, but haven't had a chance to check with PV or grid feedback yet (PV are not connected yet).

I did do some workbench testing, using a power supply instead of the battery so that I can simulate different battery voltage levels.
From my testing I have noted the following:
1. It take some time for the inverter to switch from/to battery usage, after thresholds have been met.
2. It likes to stay in bypass mode, even if it's supposed to switch to battery, if there aren't any loads, or loads are really small (say only a few 10s of watts). When I power up a load, it does switch to battery (as long as battery voltage is above "stop discharging" voltage).
3. I have noticed that while the inverter displays the battery voltage fairly accurately, the thresholds have a bit of play around them (around 0.5v).
I suppose this is to compensate for a bit if voltage sag under load or voltage measurement inaccuracy.

Can you send your manual?
I ran my in SBU output priority (solar first, PV and battery is used if solar is insufficient or not available, utility is used if solar + battery is insufficient or if battery level is too low).
Charge priority set to LBU (PV/battery used to power loads first, then charge battery, then feedback to grid any excess, if grid-feedback is enabled).

I think the EASUN and MUST are fairly similar, but not sure if features and/or settings are identical.

 

[Itschi]

My inverter behaves like you described in 1. and 3. as well. Beside the the inverter modes





there are two more settings that are of importance:

a) "On Grid": If enabled the inverter never draws power from the battery but it charges the battery. However, if not enabaled, excess energy from PV is never pushed to the grid.

b) "Charging": Here you can set the total and the AC (Grid) charging current. If you set AC current to "0" the inverter does not push the excess PV energy to Grid either. If you set it to let's say 10A you use the grid for charging as well, which I don't want if PV energy is available.

For loading the batteries from PV in the morning, I set "Battery Mode", "AC Charging 0A" and "On Grid" (PV and if needed AC are feeding load and PV is loading battery). If the batteries are almost full (SoC > 95%) I change to "AC Charging 10A" (PV excess goes to grid and battery) and at sunset I set "AC Charging 0A" and "Off Grid" (load gets powered by battery only).

What I haven't checked so far is what happens if the battery is empty before new PV energy can charge it again. Hope the inverter will switch to "AC Bypass" even if "On Grid" is disabled. I'll check what you wrote at 3. but my base load is between 100-200W. With that load the battery was not used.

 

[meetyg]

OK, so those settings are a bit different than what I expected. It seems like your "Solar" mode is equal to SOL with some MUST/MPP/GROWATT inverters.
The downside to this mode is that it will only blend battery with PV if there is any PV. If no PV available to power loads, it will switch to AC.

Sorry I couldn't help much. From the manual it does seem like the support you got is correct, it's probably not possible to do what you wanted.

 

[Itschi]

How did you change inverter modes with this inverter do you have a link?

There is an interface description I found in the net (https://github.com/jblance/mpp-solar/files/6328557/Revo.20Protocol.20V03--20201112.docx). With the PSET command you can set modes and parameters. Unfortunately specifically that command is not described correctly. You may NOT end a PSET command with <CR> as this results in a NAK -> not ok. If you skip the <CR> and use the format of the parameters as described for the PQSE command it works. Took me quite a while to find that out...

 

[Itschi]

OK, so those settings are a bit different than what I expected. It seems like your "Solar" mode is equal to SOL with some MUST/MPP/GROWATT inverters.
The downside to this mode is that it will only blend battery with PV if there is any PV. If no PV available to power loads, it will switch to AC.

Sorry I couldn't help much. From the manual it does seem like the support you got is correct, it's probably not possible to do what you wanted.

Thank you anyway. It's always good to share findings!

 

[Benson Antony]

Hi,

I’m having an issue with an EASun IGrid VE II Hybrid Solar Inverter. My setup is a PV source with 4.2kW and a LiFePO4 battery with 6.7kWh connected as “User Type”. What I’m trying to achieve is as follows:

• If PV is more than sufficient, feed load by PV, PV excess should charge the battery with priority and the remaining power should go to the grid
• If PV is insufficient, feed load from PV & Battery
• If PV is not available (e.g. during the night), feed load from battery
• If neither PV and/or battery is sufficient, use AC (bypass)

Looking at the manual I was thinking of working mode “Solar” with “En PV/AC” enabled would be my choice. It works as long as there is enough PV power available but if PV power goes below load needs, the inverter switches to “AC Bypass” instead of using the battery. Same with working mode “Battery” and “En PV/AC” enabled. As a matter of fact there is no way to get the inverter using the battery as source other than cutting the grid.

Anybody that could give advice how to proceed?

Regards, Itschi

Hi,

I am using the same exat configuration on my 5.5 kw home setup.

You must choose working mode "Battery" and set the AC charging current to very minimum.
In this mode during day time the solar will provide power to home and battery acording to the charging curent setting.
In the night first priority is from battery, if it finished then automatically changed to grid power.Day time my energy cunsuption in 24H is about 4.2kWH and I am using 200Ah 48V deep cycle lead acid battery with a maximum charging current 30A from 6.3KW solar array.

Regards,Benson

 

[Itschi]

Hi,

I am using the same exat configuration on my 5.5 kw home setup.

You must choose working mode "Battery" and set the AC charging current to very minimum.
In this mode during day time the solar will provide power to home and battery acording to the charging curent setting.
In the night first priority is from battery, if it finished then automatically changed to grid power.Day time my energy cunsuption in 24H is about 4.2kWH and I am using 200Ah 48V deep cycle lead acid battery with a maximum charging current 30A from 6.3KW solar array.

Regards,Benson

Thanks Benson,

I'm actually using the Battery Mode but as I don't want the grid to charge the battery at all but let the PV do the job, I ended up to change AC charging current with a script setting the value via RS232 to zero until the battery is full and 10A afterwords. The latter makes sure that the PV excess goes to the grid.