question

Well, It would seem the issue is related to the Limit Feed-in setting.

I had it set to 700W. This is well above a normal achievable output value. I only set it that high in the hope it might limit a spike that sometimes happens and the battery supplies 6 7 or 8 hundred watts to the grid for several seconds. Typical feed-in during full sun is less than 500W. Even tho this feed-in limit value is rarely seen, the fact that it is "Set" has the weird effect of oscillating / pulsing the feed-in power. If I set it to 1000W its no problem. So My question is...What is the limit value actually a limit of?

I figured it would be the actual value being feed in. But that does not appear to be the case.

Any ideas?

Hi @Elvis,

I believe i had a similar issue to yourself. Whereby if battery was full and solar being produced exceeds the grid limit set in ESS the mppt would ramp down to 0 then battery voltage would dip/start to discharge (even while still in absorb/float mode) and then then mppt would ramp back up to max output and exceed absorption/float voltage and that cycle would repeat. However i expected (and im guessing you did also) that the mppt would ramp down gradually not 0 to max and repeating it.

I'm still testing but enabling DVCC and specifically SVS setting (as that's the only one i have enabled), seems to have solved the problem. The MPPT seems to scale more slowly/accurately now rather than going from 0 to 100 when battery is fully and grid limit is met.

I'll confirm this is the case on my next sunny day (might be awhile I'm based in wales Uk...)

I can confirm, my previous comment was correct. Turning on svs solved my issue which seemed the same as yours.

Its possible I may have found relevant information regarding this issue.

One of my questions was "What is it actually a limit of?" (The maximum feed-in)

Well i'm pretty sure its an aggregate of all the phases. I assumed since I only have a single phase, setting it to 1200 watts that would be the actual limit. Its not, If I poll register 66 (L1) the /Hub4/L1/MaxFeedInPower it shows 600 watts. So, When I was setting it to 700 watts its actually 400 watts. The MPPT's were producing much more than that at peak output when the battery was full. That power has to be controlled somehow since its limit was 400 watts. If you look at the screen shot its only happening above 400 watts.

I dont have many good full power days left and its been raining for 8 weeks. It may be awhile before I can see if this is correct.