question

Ehm, you sayed:

I notice a pretty large DC_feedin after switching from Absorption to Float, which I cannot explain. AC and DC feed-in is allowed.

Hence where is the problem?

1) your batteries are full and the MPPT is in float

2) DC feed-in is allowed

3) the sun is probably shining

4) your MPPT can deliver more energy and it is feed-in.

There is nothing wrong with it except, that the MPPT deliver only 2048W, but the load on the battery is 4003W.

It seems, the DC feed-in is not correctly setup.

How did you setup the DC feed-in?

Without knowing your config it is hard to say, why it feed-in twice the energy from the PV

Well, my problem is, that the battery is being discharged into the grid :) You can clearly see, that the feed-in consists of PV power minus PowerUsageInHouse plus batteryDischarge. Why and where should I explicitly allow this? What dc-feed-in setup are you talking about except for the two switches in the ESS menu? Why dies this behaviour start and why would it automatically stop? :) I have the feeling that the battery is being discharged into the grid until the lower float voltage has been reached. Not sure why, there is no need to do that, but that's the reason why I want to try a higher float voltage to see if this effect would be smaller the next day.

Small update: The backfeed is much smaller with a higher float voltage. I raised float from 54 to 54.5V. This is no explanation for the effect itself, but at least something :)