I seem to have a issue that is occurring on some days, but today it is worse than usual.  Essentially there is more than enough sun, but the PV that generates is less than the load and then instead of taking from the grid, it takes power from the batteries.  I know there is enough sun because if I increase my load, my PV generation increases accordingly (but still leaves a gap between the PV and load).

My setup is 2x 5.5kw Sunsynk inverters with 13kw Solar panels and it is configured for this time of day to use grid when there isn't enough sun (time table is set to 100%).  So firstly, the PV generation shouldn't be lagging behind the load and secondly, if there wasn't enough sun, then power should be used from the grid, not the batteries.

Below are the screen shots from my app that shows with high and reduced load.  Between the two screen prints, I basically plugged my car out which dropped the load by 2.4kw, but also my PV generation.  Alternatively, if I turn the toaster on while the car is plugged in, it increases both the load and PV generation.  It seems to maintain the gap of 800-1600W difference between load and PV generation.  For reference, on a day like to day, I can easily generate over 5kw/h of PV at 5pm and during the day (like now), easily around 9kw/h.  So the amount of sun / PV generation isn't the problem.

 

Then, as I was typing this message, the sun went behind a cloud and the following happened (screen print below... it started using grid and battery).  Then after the sun came back, my PV generation jumped to 5.5kw/h with no battery being used... and then it now adjusted downwards back to have a 1.2kw/h gap / battery usage.  So it seems to me that the inverter is maintaining the gap between generation and load.

 

And now finally, after a couple of times that the sun went behind clouds, it is back to normal.  But how do I fix / resolve this on days where there are no clouds?

In all the pictures the battery is at 99/100%(basically full). Test with the battery at 50% I'm guessing the inverter is doing it to prevent feeding back a lot to the grid.

If grid feedback is allowed or possible enable it and if you see a perfect bell curve then you have your answer.

At 50%, the batteries are usually charging so then I'm generating around 9kw/h while the load is significantly lower than that.

However, this issue doesn't happen every day, but it is happening more often.  And even if it is generating less PV, then it should take the balance from the grid, not the batteries (since they need to be fully charged before going into the evening.

Today I'm running fine again.  Like I said, it is just certain random days.