I did change the local password to get in properly so that could be the reason of the issue. I’ll check it.
Edit: That was it! Thank you @Trinic
Hello you all,
I manage to manually charge and discharge my battery connected to my sma stp se.
The only thing is that I can do it by a fixt power.
My idea is to export power at the maximum rate and only use the exces power to charge my battery.
Is there anybody who can help me making such a flow?
Managed to achieve zero export using ModBus & P1. It actually is much simpler than I originally thought. You need to do some preparation easiest done via Sunny Portal ennexOS or Sunny Explorer to set up the inverter to receive remote system control commands.
Once that is done you only need to ModBus write a calc’d power % setpoint which you need to renew every minute or at least within 10 mins (which is the fallback time setting). In my case I use register 40023 which takes % with 100% written as 10000. This register needs to be renewed within the fallback time setting. So if there is some comms or Homey problem the inverter always returns to the preset max power limit (if set different from max capable power).
So for now my SMA STP 9000TL-20 inverter does zero export @ neg prices using a Homey and Homewizard P1, with a 1 min response time. With pos prices it reverts to the active power setting limit (which is also the ref for power scaling %).
Next phase is to integrate the battery in the flow and ensure PV is dominant power source.
There is the Slimladen app which might work for you and does all this automatically. I think there are more apps that do this.
It is strange that there is not a simple integrated HEMS for Homey yet.
I am trying to limit my STP8.0SE’s power output due to negative prices, but i keep running into the same error: “Failed to set the active power output. Reason: A Modbus Exception Occurred - See Response Body“
I can use the flowcard just fine for my STP3.0AV and STP4.0AV, and my paramtere settings for external communications are identical among all 3. What could be the issue and where can i find the response body?
What is the unit Id on the stp8.0se?
Try Id is 1, Id is 2 and Id is 3, maybe this can make a difference.
I have set the fallback time at 60 minutes. So i only change setpoint at hour price changemoment.
I also use 10 = 0,1% for no car attached and 100=1% for car charging (so i can change charge-speed +1A if power-surplus) and negative -10000 for unlimited import with negative prices.
I only read the SMA Datamanger M for my 3 STP15000-TL10 through Modbus-app by Homey.
Read input register 31243
Write Holding register 40023 for controling export to grid. 
all three inverter are on modbus unitID 3, if i try to change the STP8.0 to anything below 3 it gives me an error saying it needs to be at least 3. For clarity’s sake, I am Just using the flowcard, not the modbus.
Is there a place where i can find all the modbus registers for the individual STP SE versions (the STP3.0SE, 4.0 etc)? I cant seem to find a clear list online.
Jasper, do you have a hm2.0?
I’m installing the hm 2.0 today. I was hoping for a temporary sollution for the time until today. I have the feeling that we mightve already spoken to each other on tweakers. So once the manager is up ill try your sollution!
Yes I think we spoke on tweakers.
For a quick fix you should have connected di 1 and 5.
Inverter shuts down with this fix.
Can yo fix the link in the opening post of this thread?
https://www.sma.de/en/products/monitoring-control/sunny-explorer.html gives a 404 I think it should be: Sunny Explorer | SMA Solar
